diff --git a/Tests/LibWeb/Layout/expected/acid1.txt b/Tests/LibWeb/Layout/expected/acid1.txt
index 5d2c4088bd..e8d7438530 100644
--- a/Tests/LibWeb/Layout/expected/acid1.txt
+++ b/Tests/LibWeb/Layout/expected/acid1.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x420 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x420 [BFC] children: not-inline
     BlockContainer <(anonymous)> at (0,0) content-size 800x0 children: inline
       TextNode <#text>
     BlockContainer <body> at (20,20) content-size 480x380 children: not-inline
@@ -7,24 +7,24 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
         TextNode <#text>
       BlockContainer <dl> at (25,25) content-size 470x0 children: inline
         TextNode <#text>
-        BlockContainer <dt> at (40,40) content-size 49.998596x280 floating children: inline
+        BlockContainer <dt> at (40,40) content-size 49.998596x280 floating [BFC] children: inline
           line 0 width: 28.310546, height: 10, bottom: 10, baseline: 7.998046
             frag 0 from TextNode start: 0, length: 6, rect: [40,40 28.310546x10]
               "toggle"
           TextNode <#text>
         TextNode <#text>
-        BlockContainer <dd> at (135,45) content-size 340x270 floating children: not-inline
+        BlockContainer <dd> at (135,45) content-size 340x270 floating [BFC] children: not-inline
           BlockContainer <(anonymous)> at (135,45) content-size 340x0 children: inline
             TextNode <#text>
           BlockContainer <ul> at (135,45) content-size 340x0 children: inline
             TextNode <#text>
-            BlockContainer <li> at (150,60) content-size 50x90 floating children: inline
+            BlockContainer <li> at (150,60) content-size 50x90 floating [BFC] children: inline
               line 0 width: 37.880859, height: 10, bottom: 10, baseline: 7.998046
                 frag 0 from TextNode start: 0, length: 7, rect: [150,60 37.880859x10]
                   "the way"
               TextNode <#text>
             TextNode <#text>
-            BlockContainer <li#bar> at (235,55) content-size 139.977996x90 floating children: not-inline
+            BlockContainer <li#bar> at (235,55) content-size 139.977996x90 floating [BFC] children: not-inline
               BlockContainer <(anonymous)> at (235,55) content-size 139.977996x0 children: inline
                 TextNode <#text>
               BlockContainer <p> at (235,55) content-size 139.977996x10 children: inline
@@ -57,7 +57,7 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
               BlockContainer <(anonymous)> at (235,103) content-size 139.977996x0 children: inline
                 TextNode <#text>
             TextNode <#text>
-            BlockContainer <li> at (409.977996,60) content-size 50x90 floating children: inline
+            BlockContainer <li> at (409.977996,60) content-size 50x90 floating [BFC] children: inline
               line 0 width: 31.582031, height: 10, bottom: 10, baseline: 7.998046
                 frag 0 from TextNode start: 0, length: 6, rect: [409.977996,60 31.582031x10]
                   "i grow"
@@ -66,7 +66,7 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
                   "old"
               TextNode <#text>
             TextNode <#text>
-            BlockContainer <li#baz> at (145,185) content-size 100x100 floating children: inline
+            BlockContainer <li#baz> at (145,185) content-size 100x100 floating [BFC] children: inline
               line 0 width: 29.423828, height: 10, bottom: 10, baseline: 7.998046
                 frag 0 from TextNode start: 0, length: 6, rect: [145,185 29.423828x10]
                   "pluot?"
@@ -74,7 +74,7 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
             TextNode <#text>
           BlockContainer <(anonymous)> at (135,45) content-size 340x0 children: inline
             TextNode <#text>
-            BlockContainer <blockquote> at (280,195) content-size 50x90 floating children: not-inline
+            BlockContainer <blockquote> at (280,195) content-size 50x90 floating [BFC] children: not-inline
               BlockContainer <(anonymous)> at (280,195) content-size 50x0 children: inline
                 TextNode <#text>
               BlockContainer <address> at (280,195) content-size 50x20 children: inline
@@ -88,7 +88,7 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
               BlockContainer <(anonymous)> at (280,215) content-size 50x0 children: inline
                 TextNode <#text>
             TextNode <#text>
-            BlockContainer <h1> at (365,185) content-size 100x100 floating children: inline
+            BlockContainer <h1> at (365,185) content-size 100x100 floating [BFC] children: inline
               line 0 width: 56.416015, height: 10, bottom: 10, baseline: 7.998046
                 frag 0 from TextNode start: 0, length: 11, rect: [365,185 56.416015x10]
                   "sing to me,"
diff --git a/Tests/LibWeb/Layout/expected/automatic-height-of-non-replaced-abspos-element-must-not-be-negative.txt b/Tests/LibWeb/Layout/expected/automatic-height-of-non-replaced-abspos-element-must-not-be-negative.txt
index c00e615415..995b2d51ce 100644
--- a/Tests/LibWeb/Layout/expected/automatic-height-of-non-replaced-abspos-element-must-not-be-negative.txt
+++ b/Tests/LibWeb/Layout/expected/automatic-height-of-non-replaced-abspos-element-must-not-be-negative.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x0 children: not-inline
-    BlockContainer <body.outer> at (8,8) content-size 0x0 positioned children: not-inline
-      BlockContainer <div.inner> at (9,9) content-size 0x0 positioned children: inline
+  BlockContainer <html> at (0,0) content-size 800x0 [BFC] children: not-inline
+    BlockContainer <body.outer> at (8,8) content-size 0x0 positioned [BFC] children: not-inline
+      BlockContainer <div.inner> at (9,9) content-size 0x0 positioned [BFC] children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/automatic-width-of-non-replaced-abspos-element-must-not-be-negative.txt b/Tests/LibWeb/Layout/expected/automatic-width-of-non-replaced-abspos-element-must-not-be-negative.txt
index b60df89a3e..b823dd0e8d 100644
--- a/Tests/LibWeb/Layout/expected/automatic-width-of-non-replaced-abspos-element-must-not-be-negative.txt
+++ b/Tests/LibWeb/Layout/expected/automatic-width-of-non-replaced-abspos-element-must-not-be-negative.txt
@@ -1,4 +1,4 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x0 children: not-inline
-    BlockContainer <body.outer> at (8,8) content-size 0x0 positioned children: not-inline
-      BlockContainer <div.inner> at (9,9) content-size 0x0 positioned children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x0 [BFC] children: not-inline
+    BlockContainer <body.outer> at (8,8) content-size 0x0 positioned [BFC] children: not-inline
+      BlockContainer <div.inner> at (9,9) content-size 0x0 positioned [BFC] children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/blank.txt b/Tests/LibWeb/Layout/expected/blank.txt
index a662aaf9b8..c525b76fd0 100644
--- a/Tests/LibWeb/Layout/expected/blank.txt
+++ b/Tests/LibWeb/Layout/expected/blank.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x16 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x16 [BFC] children: not-inline
     BlockContainer <(anonymous)> at (0,0) content-size 800x0 children: inline
       TextNode <#text>
     BlockContainer <body> at (8,8) content-size 784x0 children: inline
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/atomic-inline-with-percentage-vertical-align.txt b/Tests/LibWeb/Layout/expected/block-and-inline/atomic-inline-with-percentage-vertical-align.txt
index 5424b971cb..06eda463f3 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/atomic-inline-with-percentage-vertical-align.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/atomic-inline-with-percentage-vertical-align.txt
@@ -1,10 +1,10 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x62.506248 children: not-inline
+  BlockContainer <html> at (1,1) content-size 798x62.506248 [BFC] children: not-inline
     BlockContainer <body> at (2,2) content-size 796x60.506248 children: inline
       line 0 width: 34, height: 28.50625, bottom: 28.50625, baseline: 28.50625
         frag 0 from BlockContainer start: 0, length: 0, rect: [4,3 30x30]
       line 1 width: 32, height: 28.506248, bottom: 60.506248, baseline: 28.50625
         frag 0 from BlockContainer start: 0, length: 0, rect: [3,35 30x30]
-      BlockContainer <div.clump> at (4,3) content-size 30x30 inline-block children: not-inline
+      BlockContainer <div.clump> at (4,3) content-size 30x30 inline-block [BFC] children: not-inline
       BreakNode <br>
-      BlockContainer <div.clump> at (3,35) content-size 30x30 inline-block children: not-inline
+      BlockContainer <div.clump> at (3,35) content-size 30x30 inline-block [BFC] children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/bfc-consider-all-currently-stacked-floats.txt b/Tests/LibWeb/Layout/expected/block-and-inline/bfc-consider-all-currently-stacked-floats.txt
index 60a5498995..8511f3a156 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/bfc-consider-all-currently-stacked-floats.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/bfc-consider-all-currently-stacked-floats.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x108 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x108 [BFC] children: not-inline
     BlockContainer <(anonymous)> at (0,0) content-size 800x0 children: inline
       TextNode <#text>
     BlockContainer <body> at (8,8) content-size 784x34.9375 children: not-inline
@@ -7,9 +7,9 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
         line 0 width: 27.640625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
           frag 0 from TextNode start: 1, length: 3, rect: [137,8 27.640625x17.46875]
             "bar"
-        BlockContainer <div.big-float> at (8,8) content-size 100x100 floating children: not-inline
+        BlockContainer <div.big-float> at (8,8) content-size 100x100 floating [BFC] children: not-inline
         TextNode <#text>
-        BlockContainer <div.xxx> at (108,8) content-size 29.109375x17.46875 floating children: inline
+        BlockContainer <div.xxx> at (108,8) content-size 29.109375x17.46875 floating [BFC] children: inline
           line 0 width: 29.109375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 3, rect: [108,8 29.109375x17.46875]
               "xxx"
@@ -20,7 +20,7 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
           frag 0 from TextNode start: 1, length: 3, rect: [130,25.46875 27.203125x17.46875]
             "baz"
         TextNode <#text>
-        BlockContainer <div.yyy> at (108,25.46875) content-size 21.515625x17.46875 floating children: inline
+        BlockContainer <div.yyy> at (108,25.46875) content-size 21.515625x17.46875 floating [BFC] children: inline
           line 0 width: 21.515625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 3, rect: [108,25.46875 21.515625x17.46875]
               "yyy"
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/bfc-float-left-break-vertically-2.txt b/Tests/LibWeb/Layout/expected/block-and-inline/bfc-float-left-break-vertically-2.txt
index ce53aa59f8..3aea1708b6 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/bfc-float-left-break-vertically-2.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/bfc-float-left-break-vertically-2.txt
@@ -1,10 +1,10 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x150 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x150 [BFC] children: not-inline
     BlockContainer <body> at (0,0) content-size 200x0 children: not-inline
       BlockContainer <ul> at (0,0) content-size 200x0 children: inline
-        BlockContainer <div.red> at (0,0) content-size 150x50 floating children: not-inline
-        BlockContainer <div.green> at (0,50) content-size 150x50 floating children: not-inline
+        BlockContainer <div.red> at (0,0) content-size 150x50 floating [BFC] children: not-inline
+        BlockContainer <div.green> at (0,50) content-size 150x50 floating [BFC] children: not-inline
         TextNode <#text>
-      BlockContainer <div.orange> at (0,100) content-size 150x50 floating children: not-inline
+      BlockContainer <div.orange> at (0,100) content-size 150x50 floating [BFC] children: not-inline
       BlockContainer <(anonymous)> at (0,0) content-size 200x0 children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/bfc-float-left-break-vertically.txt b/Tests/LibWeb/Layout/expected/block-and-inline/bfc-float-left-break-vertically.txt
index 9a28e9d6cb..3ca9e93ac1 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/bfc-float-left-break-vertically.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/bfc-float-left-break-vertically.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x106 children: not-inline
+  BlockContainer <html> at (1,1) content-size 798x106 [BFC] children: not-inline
     BlockContainer <(anonymous)> at (1,1) content-size 798x0 children: inline
       TextNode <#text>
     BlockContainer <body> at (2,2) content-size 400x2 children: not-inline
@@ -7,11 +7,11 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
         TextNode <#text>
       BlockContainer <div.ul> at (3,3) content-size 398x0 children: inline
         TextNode <#text>
-        BlockContainer <div.yellow> at (4,4) content-size 60x50 floating children: not-inline
+        BlockContainer <div.yellow> at (4,4) content-size 60x50 floating [BFC] children: not-inline
         TextNode <#text>
-        BlockContainer <div.orange> at (66,4) content-size 250x50 floating children: not-inline
+        BlockContainer <div.orange> at (66,4) content-size 250x50 floating [BFC] children: not-inline
         TextNode <#text>
       BlockContainer <(anonymous)> at (2,4) content-size 400x0 children: inline
         TextNode <#text>
-        BlockContainer <div.green> at (3,56) content-size 100x50 floating children: not-inline
+        BlockContainer <div.green> at (3,56) content-size 100x50 floating [BFC] children: not-inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/clearfix.txt b/Tests/LibWeb/Layout/expected/block-and-inline/clearfix.txt
index 8f996d0ea9..2d13a12cd7 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/clearfix.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/clearfix.txt
@@ -1,15 +1,15 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x157 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x157 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x100 children: not-inline
       BlockContainer <div> at (8,8) content-size 784x100 children: not-inline
         BlockContainer <(anonymous)> at (8,8) content-size 784x0 children: inline
           TextNode <#text>
-          BlockContainer <div.square.white> at (8,8) content-size 100x100 floating children: not-inline
+          BlockContainer <div.square.white> at (8,8) content-size 100x100 floating [BFC] children: not-inline
           TextNode <#text>
         BlockContainer <div.clearfix> at (8,108) content-size 784x0 children: not-inline
         BlockContainer <(anonymous)> at (8,108) content-size 784x0 children: inline
           TextNode <#text>
-          BlockContainer <div.square.black> at (8,108) content-size 49x49 floating children: not-inline
+          BlockContainer <div.square.black> at (8,108) content-size 49x49 floating [BFC] children: not-inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,108) content-size 784x0 children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/float-1.txt b/Tests/LibWeb/Layout/expected/block-and-inline/float-1.txt
index 139ba1a161..dc74716f43 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/float-1.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/float-1.txt
@@ -1,17 +1,17 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x348.34375 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x348.34375 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x332.34375 children: not-inline
       BlockContainer <(anonymous)> at (8,8) content-size 784x0 children: inline
         TextNode <#text>
       BlockContainer <div> at (8,8) content-size 784x0 children: inline
         TextNode <#text>
-        BlockContainer <div#lefty> at (8,8) content-size 100x100 floating children: inline
+        BlockContainer <div#lefty> at (8,8) content-size 100x100 floating [BFC] children: inline
           line 0 width: 10.859375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,8 10.859375x17.46875]
               "L"
           TextNode <#text>
         TextNode <#text>
-        BlockContainer <div#righty> at (742,8) content-size 50x50 floating children: inline
+        BlockContainer <div#righty> at (742,8) content-size 50x50 floating [BFC] children: inline
           line 0 width: 13.6875, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [742,8 13.6875x17.46875]
               "R"
@@ -21,13 +21,13 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
         TextNode <#text>
       BlockContainer <div> at (8,8) content-size 784x0 children: inline
         TextNode <#text>
-        BlockContainer <div#lefty2> at (108,8) content-size 80x80 floating children: inline
+        BlockContainer <div#lefty2> at (108,8) content-size 80x80 floating [BFC] children: inline
           line 0 width: 19.671875, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 2, rect: [108,8 19.671875x17.46875]
               "L2"
           TextNode <#text>
         TextNode <#text>
-        BlockContainer <div#righty2> at (712,8) content-size 30x30 floating children: inline
+        BlockContainer <div#righty2> at (712,8) content-size 30x30 floating [BFC] children: inline
           line 0 width: 22.5, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 2, rect: [712,8 22.5x17.46875]
               "R2"
@@ -37,13 +37,13 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
         TextNode <#text>
       BlockContainer <div> at (8,8) content-size 784x0 children: inline
         TextNode <#text>
-        BlockContainer <div#lefty3> at (188,8) content-size 40x40 floating children: inline
+        BlockContainer <div#lefty3> at (188,8) content-size 40x40 floating [BFC] children: inline
           line 0 width: 19.953125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 2, rect: [188,8 19.953125x17.46875]
               "L3"
           TextNode <#text>
         TextNode <#text>
-        BlockContainer <div#righty3> at (692,8) content-size 20x20 floating children: inline
+        BlockContainer <div#righty3> at (692,8) content-size 20x20 floating [BFC] children: inline
           line 0 width: 22.78125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 2, rect: [692,8 22.78125x17.46875]
               "R3"
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/float-2.txt b/Tests/LibWeb/Layout/expected/block-and-inline/float-2.txt
index 19dc37d752..aa78fef643 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/float-2.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/float-2.txt
@@ -1,11 +1,11 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x60 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x60 [BFC] children: not-inline
     BlockContainer <(anonymous)> at (0,0) content-size 800x0 children: inline
       TextNode <#text>
     BlockContainer <body> at (8,8) content-size 784x17.46875 children: not-inline
       BlockContainer <(anonymous)> at (8,8) content-size 784x0 children: inline
         TextNode <#text>
-        BlockContainer <div#b> at (9,9) content-size 50x50 floating children: not-inline
+        BlockContainer <div#b> at (9,9) content-size 50x50 floating [BFC] children: not-inline
         TextNode <#text>
       BlockContainer <div#a> at (8,8) content-size 784x17.46875 children: inline
         line 0 width: 37.578125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/float-3.txt b/Tests/LibWeb/Layout/expected/block-and-inline/float-3.txt
index 59b506128c..21fa72a9f7 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/float-3.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/float-3.txt
@@ -1,13 +1,13 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x135.46875 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x135.46875 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 780x119.46875 children: not-inline
       BlockContainer <(anonymous)> at (8,8) content-size 780x0 children: inline
         TextNode <#text>
-      BlockContainer <div#top> at (8,8) content-size 780x100 children: inline
+      BlockContainer <div#top> at (8,8) content-size 780x100 [BFC] children: inline
         TextNode <#text>
-        BlockContainer <div#top-left.box> at (8,8) content-size 300x100 floating children: not-inline
+        BlockContainer <div#top-left.box> at (8,8) content-size 300x100 floating [BFC] children: not-inline
         TextNode <#text>
-        BlockContainer <div#top-right.box> at (488,8) content-size 300x100 floating children: not-inline
+        BlockContainer <div#top-right.box> at (488,8) content-size 300x100 floating [BFC] children: not-inline
         TextNode <#text>
       BlockContainer <(anonymous)> at (8,108) content-size 780x0 children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/float-stress-1.txt b/Tests/LibWeb/Layout/expected/block-and-inline/float-stress-1.txt
index 58cb187ac0..951a049857 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/float-stress-1.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/float-stress-1.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x268 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x268 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x252 children: not-inline
       BlockContainer <(anonymous)> at (8,8) content-size 784x0 children: inline
         TextNode <#text>
@@ -65,15 +65,15 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
           frag 0 from TextNode start: 125, length: 19, rect: [9,269 168.84375x16]
             "bar baz foo bar baz"
         TextNode <#text>
-        BlockContainer <div.lefty> at (10,10) content-size 50x50 floating children: not-inline
+        BlockContainer <div.lefty> at (10,10) content-size 50x50 floating [BFC] children: not-inline
         TextNode <#text>
-        BlockContainer <div.one> at (62,26) content-size 200x50 floating children: not-inline
+        BlockContainer <div.one> at (62,26) content-size 200x50 floating [BFC] children: not-inline
         TextNode <#text>
-        BlockContainer <div.two> at (108,78) content-size 200x50 floating children: not-inline
+        BlockContainer <div.two> at (108,78) content-size 200x50 floating [BFC] children: not-inline
         TextNode <#text>
-        BlockContainer <div.righty> at (76,126) content-size 30x30 floating children: not-inline
+        BlockContainer <div.righty> at (76,126) content-size 30x30 floating [BFC] children: not-inline
         TextNode <#text>
-        BlockContainer <div.lefty.shwifty> at (10,174) content-size 50x50 floating children: not-inline
+        BlockContainer <div.lefty.shwifty> at (10,174) content-size 50x50 floating [BFC] children: not-inline
         TextNode <#text>
-        BlockContainer <div.righty> at (278,190) content-size 30x30 floating children: not-inline
+        BlockContainer <div.righty> at (278,190) content-size 30x30 floating [BFC] children: not-inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/float-stress-2.txt b/Tests/LibWeb/Layout/expected/block-and-inline/float-stress-2.txt
index e22fed5764..e2cd9987ef 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/float-stress-2.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/float-stress-2.txt
@@ -1,14 +1,14 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html.js> at (0,0) content-size 800x200 children: not-inline
+  BlockContainer <html.js> at (0,0) content-size 800x200 [BFC] children: not-inline
     BlockContainer <body> at (0,0) content-size 800x50 children: not-inline
       BlockContainer <div#page> at (50,50) content-size 750x0 children: not-inline
-        BlockContainer <div#content_box> at (50,50) content-size 400x150 floating children: inline
-          BlockContainer <article.first> at (50,50) content-size 300x100 floating children: inline
+        BlockContainer <div#content_box> at (50,50) content-size 400x150 floating [BFC] children: inline
+          BlockContainer <article.first> at (50,50) content-size 300x100 floating [BFC] children: inline
             line 0 width: 36.03125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
               frag 0 from TextNode start: 0, length: 5, rect: [50,50 36.03125x17.46875]
                 "first"
             TextNode <#text>
-          BlockContainer <article.second> at (50,150) content-size 200x50 floating children: inline
+          BlockContainer <article.second> at (50,150) content-size 200x50 floating [BFC] children: inline
             line 0 width: 54.78125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
               frag 0 from TextNode start: 0, length: 6, rect: [50,150 54.78125x17.46875]
                 "second"
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/float-stress-3.txt b/Tests/LibWeb/Layout/expected/block-and-inline/float-stress-3.txt
index 6cebe12ae1..db2dc0cbe3 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/float-stress-3.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/float-stress-3.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x268 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x268 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x252 children: not-inline
       BlockContainer <(anonymous)> at (8,8) content-size 784x0 children: inline
         TextNode <#text>
@@ -8,9 +8,9 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
           frag 0 from TextNode start: 1, length: 23, rect: [61,9 204x16]
             "foo bar baz foo bar baz"
         TextNode <#text>
-        BlockContainer <div.lefty> at (10,10) content-size 50x50 floating children: not-inline
+        BlockContainer <div.lefty> at (10,10) content-size 50x50 floating [BFC] children: not-inline
         TextNode <#text>
-        BlockContainer <div.one> at (62,26) content-size 200x50 floating children: not-inline
+        BlockContainer <div.one> at (62,26) content-size 200x50 floating [BFC] children: not-inline
         TextNode <#text>
-        BlockContainer <div.two> at (108,78) content-size 200x50 floating children: not-inline
+        BlockContainer <div.two> at (108,78) content-size 200x50 floating [BFC] children: not-inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/ifc-float-left-and-sibling-with-margin-left.txt b/Tests/LibWeb/Layout/expected/block-and-inline/ifc-float-left-and-sibling-with-margin-left.txt
index efc8ed23b4..de957b8a42 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/ifc-float-left-and-sibling-with-margin-left.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/ifc-float-left-and-sibling-with-margin-left.txt
@@ -1,7 +1,7 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x61 children: not-inline
+  BlockContainer <html> at (1,1) content-size 798x61 [BFC] children: not-inline
     BlockContainer <body> at (10,10) content-size 780x19.46875 children: not-inline
-      BlockContainer <div.thumbnail> at (11,11) content-size 50x50 floating children: not-inline
+      BlockContainer <div.thumbnail> at (11,11) content-size 50x50 floating [BFC] children: not-inline
       BlockContainer <div.title> at (91,11) content-size 698x17.46875 children: inline
         line 0 width: 125.125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
           frag 0 from TextNode start: 0, length: 14, rect: [91,11 125.125x17.46875]
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/inline-box-positioned-with-top-left.txt b/Tests/LibWeb/Layout/expected/block-and-inline/inline-box-positioned-with-top-left.txt
index 7a188b3bdc..f3c23769f7 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/inline-box-positioned-with-top-left.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/inline-box-positioned-with-top-left.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x36 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x36 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x20 children: inline
       line 0 width: 352.34375, height: 20, bottom: 20, baseline: 13.53125
         frag 0 from TextNode start: 0, length: 14, rect: [8,8 112.421875x17.46875]
@@ -8,7 +8,7 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
         frag 2 from TextNode start: 0, length: 16, rect: [231,8 129.546875x17.46875]
           "more inline text"
       TextNode <#text>
-      BlockContainer <span.displaced_text> at (150,48) content-size 110.375x20 positioned inline-block children: inline
+      BlockContainer <span.displaced_text> at (150,48) content-size 110.375x20 positioned inline-block [BFC] children: inline
         line 0 width: 110.375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
           frag 0 from TextNode start: 0, length: 14, rect: [150,48 110.375x17.46875]
             "displaced text"
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/inline-box-with-vertical-margins-vertical-align-top.txt b/Tests/LibWeb/Layout/expected/block-and-inline/inline-box-with-vertical-margins-vertical-align-top.txt
index c15b1aeece..366226d7ef 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/inline-box-with-vertical-margins-vertical-align-top.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/inline-box-with-vertical-margins-vertical-align-top.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x191 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x191 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x175 children: inline
       line 0 width: 210.828125, height: 175, bottom: 175, baseline: 13.53125
         frag 0 from TextNode start: 0, length: 6, rect: [8,8 43.125x17.46875]
@@ -8,5 +8,5 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
         frag 2 from TextNode start: 0, length: 9, rect: [151,8 67.703125x17.46875]
           " friends."
       TextNode <#text>
-      BlockContainer <div#inline-box> at (51,58) content-size 100x100 inline-block children: not-inline
+      BlockContainer <div#inline-box> at (51,58) content-size 100x100 inline-block [BFC] children: not-inline
       TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/inline-box-with-vertical-margins.txt b/Tests/LibWeb/Layout/expected/block-and-inline/inline-box-with-vertical-margins.txt
index cb06afebbd..1bf013266f 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/inline-box-with-vertical-margins.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/inline-box-with-vertical-margins.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x194.46875 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x194.46875 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x178.46875 children: inline
       line 0 width: 210.828125, height: 178.46875, bottom: 178.46875, baseline: 175
         frag 0 from TextNode start: 0, length: 6, rect: [8,169 43.125x17.46875]
@@ -8,5 +8,5 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
         frag 2 from TextNode start: 0, length: 9, rect: [151,169 67.703125x17.46875]
           " friends."
       TextNode <#text>
-      BlockContainer <div#inline-box> at (51,58) content-size 100x100 inline-block children: not-inline
+      BlockContainer <div#inline-box> at (51,58) content-size 100x100 inline-block [BFC] children: not-inline
       TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/intrinsic-sizing-with-min-width-specified.txt b/Tests/LibWeb/Layout/expected/block-and-inline/intrinsic-sizing-with-min-width-specified.txt
index 36aeea9e0f..fdff3c3ed9 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/intrinsic-sizing-with-min-width-specified.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/intrinsic-sizing-with-min-width-specified.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x52 children: not-inline
-    BlockContainer <body> at (10,10) content-size 104x34 floating children: not-inline
+  BlockContainer <html> at (1,1) content-size 798x52 [BFC] children: not-inline
+    BlockContainer <body> at (10,10) content-size 104x34 floating [BFC] children: not-inline
       BlockContainer <div.outer> at (11,11) content-size 102x32 children: not-inline
         BlockContainer <div.inner> at (12,12) content-size 100x30 children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/join-out-of-flow-box-with-previous-sibling-if-wrapped-in-anonymous-box.txt b/Tests/LibWeb/Layout/expected/block-and-inline/join-out-of-flow-box-with-previous-sibling-if-wrapped-in-anonymous-box.txt
index e9a9081597..7ea9fdbac5 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/join-out-of-flow-box-with-previous-sibling-if-wrapped-in-anonymous-box.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/join-out-of-flow-box-with-previous-sibling-if-wrapped-in-anonymous-box.txt
@@ -1,9 +1,9 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x76 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x76 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x60 children: not-inline
       BlockContainer <div.banner> at (8,8) content-size 200x30 children: not-inline
       BlockContainer <(anonymous)> at (8,38) content-size 784x30 children: inline
         line 0 width: 200, height: 30, bottom: 30, baseline: 30
           frag 0 from BlockContainer start: 0, length: 0, rect: [8,38 200x30]
-        BlockContainer <div.tab> at (8,38) content-size 200x30 inline-block children: not-inline
-        BlockContainer <div.timeline> at (592,38) content-size 200x30 floating children: not-inline
+        BlockContainer <div.tab> at (8,38) content-size 200x30 inline-block [BFC] children: not-inline
+        BlockContainer <div.timeline> at (592,38) content-size 200x30 floating [BFC] children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/margin-collapse-1.txt b/Tests/LibWeb/Layout/expected/block-and-inline/margin-collapse-1.txt
index 6d4a943f0b..39e4b8ea84 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/margin-collapse-1.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/margin-collapse-1.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x262 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x262 [BFC] children: not-inline
     BlockContainer <body> at (8,25) content-size 784x229 children: not-inline
       BlockContainer <div#foo> at (34,26) content-size 100x100 children: inline
         line 0 width: 27.15625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/margin-collapse-2.txt b/Tests/LibWeb/Layout/expected/block-and-inline/margin-collapse-2.txt
index 41a717a357..b12a5b836d 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/margin-collapse-2.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/margin-collapse-2.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x352 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x352 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x336 children: not-inline
       BlockContainer <div#foo> at (9,9) content-size 100x100 children: inline
         line 0 width: 27.15625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/margin-collapse-3.txt b/Tests/LibWeb/Layout/expected/block-and-inline/margin-collapse-3.txt
index c962b55524..6953e5e0fc 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/margin-collapse-3.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/margin-collapse-3.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x366 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x366 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x350 children: not-inline
       BlockContainer <div#foo> at (8,8) content-size 100x100 children: not-inline
       BlockContainer <(anonymous)> at (8,133) content-size 784x0 children: inline
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/margin-collapse-4.txt b/Tests/LibWeb/Layout/expected/block-and-inline/margin-collapse-4.txt
index 4f409a7bb5..04ba1180b7 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/margin-collapse-4.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/margin-collapse-4.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x166 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x166 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x150 children: not-inline
       BlockContainer <div#foo> at (8,8) content-size 100x50 children: not-inline
         BlockContainer <div#baz> at (8,8) content-size 50x50 children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/margin-collapse-5.txt b/Tests/LibWeb/Layout/expected/block-and-inline/margin-collapse-5.txt
index 2f740ec5d7..1a092d3a83 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/margin-collapse-5.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/margin-collapse-5.txt
@@ -1,8 +1,8 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x134.46875 children: inline
+  BlockContainer <html> at (1,1) content-size 798x134.46875 [BFC] children: inline
     line 0 width: 170.96875, height: 134.46875, bottom: 134.46875, baseline: 13.53125
       frag 0 from BlockContainer start: 0, length: 0, rect: [2,15 168.96875x119.46875]
-    BlockContainer <body> at (2,15) content-size 168.96875x119.46875 inline-block children: not-inline
+    BlockContainer <body> at (2,15) content-size 168.96875x119.46875 inline-block [BFC] children: not-inline
       BlockContainer <div.hmm> at (3,16) content-size 166.96875x17.46875 children: inline
         line 0 width: 166.96875, height: 17.46875, bottom: 17.46875, baseline: 13.53125
           frag 0 from TextNode start: 0, length: 21, rect: [3,16 166.96875x17.46875]
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/max-width-on-child-block-with-width-auto-contributes-to-intrinsic-size-of-parent.txt b/Tests/LibWeb/Layout/expected/block-and-inline/max-width-on-child-block-with-width-auto-contributes-to-intrinsic-size-of-parent.txt
index 39151e8cab..6912a85853 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/max-width-on-child-block-with-width-auto-contributes-to-intrinsic-size-of-parent.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/max-width-on-child-block-with-width-auto-contributes-to-intrinsic-size-of-parent.txt
@@ -1,7 +1,7 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x39.46875 children: not-inline
-    Box <body.outer> at (10,10) content-size 764x21.46875 flex-container(row) children: not-inline
-      BlockContainer <div.middle> at (11,11) content-size 202x19.46875 flex-item children: not-inline
+  BlockContainer <html> at (1,1) content-size 798x39.46875 [BFC] children: not-inline
+    Box <body.outer> at (10,10) content-size 764x21.46875 flex-container(row) [FFC] children: not-inline
+      BlockContainer <div.middle> at (11,11) content-size 202x19.46875 flex-item [BFC] children: not-inline
         BlockContainer <div.inner> at (12,12) content-size 200x17.46875 children: inline
           line 0 width: 45.15625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 4, rect: [12,12 45.15625x17.46875]
diff --git a/Tests/LibWeb/Layout/expected/block-and-inline/single-br-inline-layout.txt b/Tests/LibWeb/Layout/expected/block-and-inline/single-br-inline-layout.txt
index 9e37d696c6..be8191cf70 100644
--- a/Tests/LibWeb/Layout/expected/block-and-inline/single-br-inline-layout.txt
+++ b/Tests/LibWeb/Layout/expected/block-and-inline/single-br-inline-layout.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x37.46875 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x37.46875 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x21.46875 children: not-inline
       BlockContainer <div#begin> at (8,8) content-size 784x2 children: not-inline
       BlockContainer <(anonymous)> at (8,10) content-size 784x17.46875 children: inline
diff --git a/Tests/LibWeb/Layout/expected/box-sizing-border-box-for-definite-sizes-without-layout.txt b/Tests/LibWeb/Layout/expected/box-sizing-border-box-for-definite-sizes-without-layout.txt
index f79242478a..28392dbc3e 100644
--- a/Tests/LibWeb/Layout/expected/box-sizing-border-box-for-definite-sizes-without-layout.txt
+++ b/Tests/LibWeb/Layout/expected/box-sizing-border-box-for-definite-sizes-without-layout.txt
@@ -1,10 +1,10 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x66 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x66 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x50 children: inline
       line 0 width: 89.726562, height: 50, bottom: 50, baseline: 16.914062
         frag 0 from Box start: 0, length: 0, rect: [28,38 49.726562x0]
-      Box <div.button> at (28,38) content-size 49.726562x0 flex-container(row) children: not-inline
-        BlockContainer <(anonymous)> at (28,27.082031) content-size 49.726562x21.835937 flex-item children: inline
+      Box <div.button> at (28,38) content-size 49.726562x0 flex-container(row) [FFC] children: not-inline
+        BlockContainer <(anonymous)> at (28,27.082031) content-size 49.726562x21.835937 flex-item [BFC] children: inline
           line 0 width: 49.726562, height: 21.835937, bottom: 21.835937, baseline: 16.914062
             frag 0 from TextNode start: 0, length: 5, rect: [28,27.082031 49.726562x21.835937]
               "Hello"
diff --git a/Tests/LibWeb/Layout/expected/css-import-rule.txt b/Tests/LibWeb/Layout/expected/css-import-rule.txt
index 075781c7b7..6c7d1d9a77 100644
--- a/Tests/LibWeb/Layout/expected/css-import-rule.txt
+++ b/Tests/LibWeb/Layout/expected/css-import-rule.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x70.589843 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x70.589843 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x54.589843 children: inline
       line 0 width: 137.646484, height: 54.589843, bottom: 54.589843, baseline: 42.285156
         frag 0 from TextNode start: 0, length: 5, rect: [8,8 137.646484x54.589843]
diff --git a/Tests/LibWeb/Layout/expected/css-imported-sheet-with-media-rule.txt b/Tests/LibWeb/Layout/expected/css-imported-sheet-with-media-rule.txt
index 1769f5d796..698c98615e 100644
--- a/Tests/LibWeb/Layout/expected/css-imported-sheet-with-media-rule.txt
+++ b/Tests/LibWeb/Layout/expected/css-imported-sheet-with-media-rule.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x125.179687 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x125.179687 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x109.179687 children: inline
       line 0 width: 275.292968, height: 109.179687, bottom: 109.179687, baseline: 84.570312
         frag 0 from TextNode start: 0, length: 5, rect: [8,8 275.292968x109.179687]
diff --git a/Tests/LibWeb/Layout/expected/css-line-height-percentage-inheritance.txt b/Tests/LibWeb/Layout/expected/css-line-height-percentage-inheritance.txt
index be7033268c..91855e7c53 100644
--- a/Tests/LibWeb/Layout/expected/css-line-height-percentage-inheritance.txt
+++ b/Tests/LibWeb/Layout/expected/css-line-height-percentage-inheritance.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x52 children: not-inline
+  BlockContainer <html> at (1,1) content-size 798x52 [BFC] children: not-inline
     BlockContainer <body> at (10,10) content-size 780x34 children: not-inline
       BlockContainer <div> at (11,11) content-size 778x32 children: inline
         line 0 width: 552.109375, height: 32, bottom: 32, baseline: 27.992187
diff --git a/Tests/LibWeb/Layout/expected/css-pseudo-element-blockification.txt b/Tests/LibWeb/Layout/expected/css-pseudo-element-blockification.txt
index 03ec5cf771..e572ed788d 100644
--- a/Tests/LibWeb/Layout/expected/css-pseudo-element-blockification.txt
+++ b/Tests/LibWeb/Layout/expected/css-pseudo-element-blockification.txt
@@ -1,18 +1,18 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x33.46875 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x33.46875 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x17.46875 children: not-inline
-      Box <div.foo> at (8,8) content-size 784x17.46875 flex-container(row) children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 28.40625x17.46875 flex-item children: inline
+      Box <div.foo> at (8,8) content-size 784x17.46875 flex-container(row) [FFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 28.40625x17.46875 flex-item [BFC] children: inline
           line 0 width: 28.40625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 4, rect: [8,8 28.40625x17.46875]
               "well"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (46,8) content-size 36.84375x17.46875 flex-item children: inline
+        BlockContainer <(anonymous)> at (46,8) content-size 36.84375x17.46875 flex-item [BFC] children: inline
           line 0 width: 36.84375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 5, rect: [46,8 36.84375x17.46875]
               "hello"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (92.4375,8) content-size 55.359375x17.46875 flex-item children: inline
+        BlockContainer <(anonymous)> at (92.4375,8) content-size 55.359375x17.46875 flex-item [BFC] children: inline
           line 0 width: 55.359375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 7, rect: [92.4375,8 55.359375x17.46875]
               "friends"
diff --git a/Tests/LibWeb/Layout/expected/css-pseudo-element-should-not-be-affected-by-inline-style.txt b/Tests/LibWeb/Layout/expected/css-pseudo-element-should-not-be-affected-by-inline-style.txt
index 4aa2d67800..2561394caf 100644
--- a/Tests/LibWeb/Layout/expected/css-pseudo-element-should-not-be-affected-by-inline-style.txt
+++ b/Tests/LibWeb/Layout/expected/css-pseudo-element-should-not-be-affected-by-inline-style.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x120 children: not-inline
+  BlockContainer <html> at (1,1) content-size 798x120 [BFC] children: not-inline
     BlockContainer <body> at (10,10) content-size 780x102 children: not-inline
       BlockContainer <div.outer> at (11,11) content-size 100x100 children: not-inline
         BlockContainer <(anonymous)> at (12,12) content-size 50x50 children: inline
diff --git a/Tests/LibWeb/Layout/expected/css-pseudo-element-should-not-be-affected-by-presentational-hints.txt b/Tests/LibWeb/Layout/expected/css-pseudo-element-should-not-be-affected-by-presentational-hints.txt
index 388dd14f73..78dbe03867 100644
--- a/Tests/LibWeb/Layout/expected/css-pseudo-element-should-not-be-affected-by-presentational-hints.txt
+++ b/Tests/LibWeb/Layout/expected/css-pseudo-element-should-not-be-affected-by-presentational-hints.txt
@@ -1,11 +1,11 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x120 children: not-inline
+  BlockContainer <html> at (1,1) content-size 798x120 [BFC] children: not-inline
     BlockContainer <body> at (10,10) content-size 780x102 children: not-inline
-      TableWrapper <(anonymous)> at (10,10) content-size 102x102 children: not-inline
-        TableBox <table> at (11,11) content-size 102x100 children: not-inline
+      TableWrapper <(anonymous)> at (10,10) content-size 102x102 [BFC] children: not-inline
+        TableBox <table> at (11,11) content-size 102x100 [TFC] children: not-inline
           TableRowGroupBox <tbody> at (11,11) content-size 102x100 children: not-inline
             TableRowBox <tr> at (11,11) content-size 102x100 children: not-inline
-              TableCellBox <td> at (13,49.082031) content-size 98x23.835937 children: not-inline
+              TableCellBox <td> at (13,49.082031) content-size 98x23.835937 [BFC] children: not-inline
                 BlockContainer <(anonymous)> at (14,50.082031) content-size 96x21.835937 children: inline
                   line 0 width: 0, height: 21.835937, bottom: 21.835937, baseline: 16.914062
                     frag 0 from TextNode start: 0, length: 0, rect: [14,50.082031 0x21.835937]
diff --git a/Tests/LibWeb/Layout/expected/flex-abspos-item-with-preceding-whitespace.txt b/Tests/LibWeb/Layout/expected/flex-abspos-item-with-preceding-whitespace.txt
index 7fa013d846..97b364d2c0 100644
--- a/Tests/LibWeb/Layout/expected/flex-abspos-item-with-preceding-whitespace.txt
+++ b/Tests/LibWeb/Layout/expected/flex-abspos-item-with-preceding-whitespace.txt
@@ -1,7 +1,7 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x20 children: not-inline
+  BlockContainer <html> at (1,1) content-size 798x20 [BFC] children: not-inline
     BlockContainer <body> at (10,10) content-size 780x2 children: not-inline
-      Box <div.pink> at (11,11) content-size 778x0 flex-container(row) children: not-inline
-        BlockContainer <(anonymous)> at (11,11) content-size 0x0 children: inline
+      Box <div.pink> at (11,11) content-size 778x0 flex-container(row) [FFC] children: not-inline
+        BlockContainer <(anonymous)> at (11,11) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.orange> at (11,-39) content-size 100x100 positioned children: not-inline
+        BlockContainer <div.orange> at (11,-39) content-size 100x100 positioned [BFC] children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/flex-auto.txt b/Tests/LibWeb/Layout/expected/flex-auto.txt
index b3cf7d076b..c9466c77d5 100644
--- a/Tests/LibWeb/Layout/expected/flex-auto.txt
+++ b/Tests/LibWeb/Layout/expected/flex-auto.txt
@@ -1,29 +1,29 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x120 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x120 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x104 children: not-inline
-      Box <div.container> at (9,9) content-size 500x102 flex-container(row) children: not-inline
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+      Box <div.container> at (9,9) content-size 500x102 flex-container(row) [FFC] children: not-inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,10) content-size 164.666671x100 flex-item children: inline
+        BlockContainer <div.box> at (10,10) content-size 164.666671x100 flex-item [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,10 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (176.666671,10) content-size 164.666671x100 flex-item children: inline
+        BlockContainer <div.box> at (176.666671,10) content-size 164.666671x100 flex-item [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [176.666671,10 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (343.333343,10) content-size 164.666671x100 flex-item children: inline
+        BlockContainer <div.box> at (343.333343,10) content-size 164.666671x100 flex-item [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [343.333343,10 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,112) content-size 784x0 children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/flex-column-constained-wrap.txt b/Tests/LibWeb/Layout/expected/flex-column-constained-wrap.txt
index 0158cb1460..65e3adabbc 100644
--- a/Tests/LibWeb/Layout/expected/flex-column-constained-wrap.txt
+++ b/Tests/LibWeb/Layout/expected/flex-column-constained-wrap.txt
@@ -1,29 +1,29 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x268 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x268 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x252 children: not-inline
-      Box <div.container.column> at (9,9) content-size 250x250 flex-container(column) children: not-inline
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+      Box <div.container.column> at (9,9) content-size 250x250 flex-container(column) [FFC] children: not-inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,10) content-size 100x100 flex-item children: inline
+        BlockContainer <div.box> at (10,10) content-size 100x100 flex-item [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,10 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,112) content-size 100x100 flex-item children: inline
+        BlockContainer <div.box> at (10,112) content-size 100x100 flex-item [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,112 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (135,10) content-size 100x100 flex-item children: inline
+        BlockContainer <div.box> at (135,10) content-size 100x100 flex-item [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [135,10 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,260) content-size 784x0 children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/flex-column-constrained-nowrap.txt b/Tests/LibWeb/Layout/expected/flex-column-constrained-nowrap.txt
index 79eb399659..71af2896d2 100644
--- a/Tests/LibWeb/Layout/expected/flex-column-constrained-nowrap.txt
+++ b/Tests/LibWeb/Layout/expected/flex-column-constrained-nowrap.txt
@@ -1,29 +1,29 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x268 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x268 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x252 children: not-inline
-      Box <div.container.column> at (9,9) content-size 782x250 flex-container(column) children: not-inline
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+      Box <div.container.column> at (9,9) content-size 782x250 flex-container(column) [FFC] children: not-inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,10) content-size 100x81.333328 flex-item children: inline
+        BlockContainer <div.box> at (10,10) content-size 100x81.333328 flex-item [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,10 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,93.333328) content-size 100x81.333328 flex-item children: inline
+        BlockContainer <div.box> at (10,93.333328) content-size 100x81.333328 flex-item [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,93.333328 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,176.666656) content-size 100x81.333328 flex-item children: inline
+        BlockContainer <div.box> at (10,176.666656) content-size 100x81.333328 flex-item [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,176.666656 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,260) content-size 784x0 children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/flex-column-height-constrained-width-constrained.txt b/Tests/LibWeb/Layout/expected/flex-column-height-constrained-width-constrained.txt
index 65827d95df..b631fa2dda 100644
--- a/Tests/LibWeb/Layout/expected/flex-column-height-constrained-width-constrained.txt
+++ b/Tests/LibWeb/Layout/expected/flex-column-height-constrained-width-constrained.txt
@@ -1,29 +1,29 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x268 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x268 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x252 children: not-inline
-      Box <div.container.column> at (9,9) content-size 250x250 flex-container(column) children: not-inline
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+      Box <div.container.column> at (9,9) content-size 250x250 flex-container(column) [FFC] children: not-inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,10) content-size 100x81.333328 flex-item children: inline
+        BlockContainer <div.box> at (10,10) content-size 100x81.333328 flex-item [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,10 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,93.333328) content-size 100x81.333328 flex-item children: inline
+        BlockContainer <div.box> at (10,93.333328) content-size 100x81.333328 flex-item [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,93.333328 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,176.666656) content-size 100x81.333328 flex-item children: inline
+        BlockContainer <div.box> at (10,176.666656) content-size 100x81.333328 flex-item [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,176.666656 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,260) content-size 784x0 children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/flex-column-height-constrained.txt b/Tests/LibWeb/Layout/expected/flex-column-height-constrained.txt
index edf540d06e..48fc2ac5d6 100644
--- a/Tests/LibWeb/Layout/expected/flex-column-height-constrained.txt
+++ b/Tests/LibWeb/Layout/expected/flex-column-height-constrained.txt
@@ -1,29 +1,29 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x268 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x268 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x252 children: not-inline
-      Box <div.container> at (9,9) content-size 782x250 flex-container(column) children: not-inline
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+      Box <div.container> at (9,9) content-size 782x250 flex-container(column) [FFC] children: not-inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,10) content-size 100x81.333328 flex-item children: inline
+        BlockContainer <div.box> at (10,10) content-size 100x81.333328 flex-item [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,10 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,93.333328) content-size 100x81.333328 flex-item children: inline
+        BlockContainer <div.box> at (10,93.333328) content-size 100x81.333328 flex-item [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,93.333328 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,176.666656) content-size 100x81.333328 flex-item children: inline
+        BlockContainer <div.box> at (10,176.666656) content-size 100x81.333328 flex-item [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,176.666656 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,260) content-size 784x0 children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/flex-column-height-unconstrained.txt b/Tests/LibWeb/Layout/expected/flex-column-height-unconstrained.txt
index cbeb91b8b4..38ef493dc5 100644
--- a/Tests/LibWeb/Layout/expected/flex-column-height-unconstrained.txt
+++ b/Tests/LibWeb/Layout/expected/flex-column-height-unconstrained.txt
@@ -1,29 +1,29 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x324 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x324 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x308 children: not-inline
-      Box <div.my-container.column> at (9,9) content-size 782x306 flex-container(column) children: not-inline
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+      Box <div.my-container.column> at (9,9) content-size 782x306 flex-container(column) [FFC] children: not-inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,10) content-size 100x100 flex-item children: inline
+        BlockContainer <div.box> at (10,10) content-size 100x100 flex-item [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,10 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,112) content-size 100x100 flex-item children: inline
+        BlockContainer <div.box> at (10,112) content-size 100x100 flex-item [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,112 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,214) content-size 100x100 flex-item children: inline
+        BlockContainer <div.box> at (10,214) content-size 100x100 flex-item [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,214 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,316) content-size 784x0 children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/flex-column-item-with-auto-height-and-max-width.txt b/Tests/LibWeb/Layout/expected/flex-column-item-with-auto-height-and-max-width.txt
index 0154554c50..2b4f4e2e83 100644
--- a/Tests/LibWeb/Layout/expected/flex-column-item-with-auto-height-and-max-width.txt
+++ b/Tests/LibWeb/Layout/expected/flex-column-item-with-auto-height-and-max-width.txt
@@ -1,7 +1,7 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x92.21875 children: not-inline
-    Box <body> at (2,2) content-size 796x90.21875 flex-container(column) children: not-inline
-      BlockContainer <main> at (3,3) content-size 400x88.21875 flex-item children: inline
+  BlockContainer <html> at (1,1) content-size 798x92.21875 [BFC] children: not-inline
+    Box <body> at (2,2) content-size 796x90.21875 flex-container(column) [FFC] children: not-inline
+      BlockContainer <main> at (3,3) content-size 400x88.21875 flex-item [BFC] children: inline
         line 0 width: 346.984375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
           frag 0 from TextNode start: 0, length: 41, rect: [3,3 346.984375x17.46875]
             "For my day job I'm currently working as a"
diff --git a/Tests/LibWeb/Layout/expected/flex-column-item-with-auto-height-depending-auto-width-with-max-width-constraint.txt b/Tests/LibWeb/Layout/expected/flex-column-item-with-auto-height-depending-auto-width-with-max-width-constraint.txt
index 310cba1eb4..9d7b6b9535 100644
--- a/Tests/LibWeb/Layout/expected/flex-column-item-with-auto-height-depending-auto-width-with-max-width-constraint.txt
+++ b/Tests/LibWeb/Layout/expected/flex-column-item-with-auto-height-depending-auto-width-with-max-width-constraint.txt
@@ -1,7 +1,7 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x331.570312 children: not-inline
-    Box <body.hero> at (2,2) content-size 600x329.570312 flex-container(column) children: not-inline
-      BlockContainer <div.header> at (102,3) content-size 400x327.570312 flex-item children: inline
+  BlockContainer <html> at (1,1) content-size 798x331.570312 [BFC] children: not-inline
+    Box <body.hero> at (2,2) content-size 600x329.570312 flex-container(column) [FFC] children: not-inline
+      BlockContainer <div.header> at (102,3) content-size 400x327.570312 flex-item [BFC] children: inline
         line 0 width: 340.488281, height: 65.507812, bottom: 65.507812, baseline: 50.742187
           frag 0 from TextNode start: 0, length: 11, rect: [102,3 340.488281x65.507812]
             "This entire"
diff --git a/Tests/LibWeb/Layout/expected/flex-column-item-with-auto-height-depending-on-auto-width.txt b/Tests/LibWeb/Layout/expected/flex-column-item-with-auto-height-depending-on-auto-width.txt
index 7a43441486..7340131793 100644
--- a/Tests/LibWeb/Layout/expected/flex-column-item-with-auto-height-depending-on-auto-width.txt
+++ b/Tests/LibWeb/Layout/expected/flex-column-item-with-auto-height-depending-on-auto-width.txt
@@ -1,7 +1,7 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x457.09375 children: not-inline
-    Box <body.hero> at (10,10) content-size 500x439.09375 flex-container(column) children: not-inline
-      BlockContainer <div.upper> at (10,11) content-size 500x437.09375 flex-item children: inline
+  BlockContainer <html> at (1,1) content-size 798x457.09375 [BFC] children: not-inline
+    Box <body.hero> at (10,10) content-size 500x439.09375 flex-container(column) [FFC] children: not-inline
+      BlockContainer <div.upper> at (10,11) content-size 500x437.09375 flex-item [BFC] children: inline
         line 0 width: 453.984375, height: 87.34375, bottom: 87.34375, baseline: 67.65625
           frag 0 from TextNode start: 0, length: 11, rect: [10,11 453.984375x87.34375]
             "This entire"
@@ -18,5 +18,5 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
           frag 0 from TextNode start: 37, length: 11, rect: [10,360 468.75x87.34375]
             "background."
         TextNode <#text>
-      BlockContainer <(anonymous)> at (10,10) content-size 0x0 children: inline
+      BlockContainer <(anonymous)> at (10,10) content-size 0x0 [BFC] children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/flex-container-constrained-nowrap.txt b/Tests/LibWeb/Layout/expected/flex-container-constrained-nowrap.txt
index b483521da3..937d31bdc1 100644
--- a/Tests/LibWeb/Layout/expected/flex-container-constrained-nowrap.txt
+++ b/Tests/LibWeb/Layout/expected/flex-container-constrained-nowrap.txt
@@ -1,29 +1,29 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x120 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x120 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x104 children: not-inline
-      Box <div.container> at (9,9) content-size 250x102 flex-container(row) children: not-inline
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+      Box <div.container> at (9,9) content-size 250x102 flex-container(row) [FFC] children: not-inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,10) content-size 81.333328x100 flex-item children: inline
+        BlockContainer <div.box> at (10,10) content-size 81.333328x100 flex-item [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,10 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (93.333328,10) content-size 81.333328x100 flex-item children: inline
+        BlockContainer <div.box> at (93.333328,10) content-size 81.333328x100 flex-item [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [93.333328,10 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (176.666656,10) content-size 81.333328x100 flex-item children: inline
+        BlockContainer <div.box> at (176.666656,10) content-size 81.333328x100 flex-item [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [176.666656,10 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,112) content-size 784x0 children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/flex-container-constrained-wrap.txt b/Tests/LibWeb/Layout/expected/flex-container-constrained-wrap.txt
index 2c9774caed..591722473b 100644
--- a/Tests/LibWeb/Layout/expected/flex-container-constrained-wrap.txt
+++ b/Tests/LibWeb/Layout/expected/flex-container-constrained-wrap.txt
@@ -1,29 +1,29 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x222 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x222 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x206 children: not-inline
-      Box <div.container> at (9,9) content-size 250x204 flex-container(row) children: not-inline
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+      Box <div.container> at (9,9) content-size 250x204 flex-container(row) [FFC] children: not-inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,10) content-size 100x100 flex-item children: inline
+        BlockContainer <div.box> at (10,10) content-size 100x100 flex-item [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,10 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (112,10) content-size 100x100 flex-item children: inline
+        BlockContainer <div.box> at (112,10) content-size 100x100 flex-item [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [112,10 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,112) content-size 100x100 flex-item children: inline
+        BlockContainer <div.box> at (10,112) content-size 100x100 flex-item [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,112 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,214) content-size 784x0 children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/flex-container-width-constrained.txt b/Tests/LibWeb/Layout/expected/flex-container-width-constrained.txt
index a779abf4ba..a975336ea4 100644
--- a/Tests/LibWeb/Layout/expected/flex-container-width-constrained.txt
+++ b/Tests/LibWeb/Layout/expected/flex-container-width-constrained.txt
@@ -1,29 +1,29 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x120 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x120 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x104 children: not-inline
-      Box <div.container.width-constrained> at (9,9) content-size 250x102 flex-container(row) children: not-inline
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+      Box <div.container.width-constrained> at (9,9) content-size 250x102 flex-container(row) [FFC] children: not-inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,10) content-size 81.333328x100 flex-item children: inline
+        BlockContainer <div.box> at (10,10) content-size 81.333328x100 flex-item [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,10 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (93.333328,10) content-size 81.333328x100 flex-item children: inline
+        BlockContainer <div.box> at (93.333328,10) content-size 81.333328x100 flex-item [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [93.333328,10 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (176.666656,10) content-size 81.333328x100 flex-item children: inline
+        BlockContainer <div.box> at (176.666656,10) content-size 81.333328x100 flex-item [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [176.666656,10 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,112) content-size 784x0 children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/flex-frozen-items-should-be-respected.txt b/Tests/LibWeb/Layout/expected/flex-frozen-items-should-be-respected.txt
index 7fbe1d131c..adbea8708e 100644
--- a/Tests/LibWeb/Layout/expected/flex-frozen-items-should-be-respected.txt
+++ b/Tests/LibWeb/Layout/expected/flex-frozen-items-should-be-respected.txt
@@ -1,28 +1,28 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x70 children: not-inline
+  BlockContainer <html> at (1,1) content-size 798x70 [BFC] children: not-inline
     BlockContainer <body> at (10,10) content-size 780x52 children: not-inline
-      Box <div.flexbox> at (11,11) content-size 778x50 flex-container(row) children: not-inline
-        BlockContainer <div> at (12,12) content-size 136.3125x48 flex-item children: inline
+      Box <div.flexbox> at (11,11) content-size 778x50 flex-container(row) [FFC] children: not-inline
+        BlockContainer <div> at (12,12) content-size 136.3125x48 flex-item [BFC] children: inline
           line 0 width: 136.3125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 15, rect: [12,12 136.3125x17.46875]
               "LongPieceOfText"
           TextNode <#text>
-        BlockContainer <div> at (150.3125,12) content-size 136.3125x48 flex-item children: inline
+        BlockContainer <div> at (150.3125,12) content-size 136.3125x48 flex-item [BFC] children: inline
           line 0 width: 136.3125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 15, rect: [150.3125,12 136.3125x17.46875]
               "LongPieceOfText"
           TextNode <#text>
-        BlockContainer <div> at (288.625,12) content-size 136.3125x48 flex-item children: inline
+        BlockContainer <div> at (288.625,12) content-size 136.3125x48 flex-item [BFC] children: inline
           line 0 width: 136.3125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 15, rect: [288.625,12 136.3125x17.46875]
               "LongPieceOfText"
           TextNode <#text>
-        BlockContainer <div> at (426.9375,12) content-size 136.3125x48 flex-item children: inline
+        BlockContainer <div> at (426.9375,12) content-size 136.3125x48 flex-item [BFC] children: inline
           line 0 width: 136.3125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 15, rect: [426.9375,12 136.3125x17.46875]
               "LongPieceOfText"
           TextNode <#text>
-        BlockContainer <div.last.item> at (565.25,12) content-size 222.75x48 flex-item children: inline
+        BlockContainer <div.last.item> at (565.25,12) content-size 222.75x48 flex-item [BFC] children: inline
           line 0 width: 136.3125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 15, rect: [565.25,12 136.3125x17.46875]
               "LongPieceOfText"
diff --git a/Tests/LibWeb/Layout/expected/flex-grow-0-column.txt b/Tests/LibWeb/Layout/expected/flex-grow-0-column.txt
index 0474f65e00..78707e3ee8 100644
--- a/Tests/LibWeb/Layout/expected/flex-grow-0-column.txt
+++ b/Tests/LibWeb/Layout/expected/flex-grow-0-column.txt
@@ -1,29 +1,29 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x76.40625 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x76.40625 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x60.40625 children: not-inline
-      Box <div.container> at (9,9) content-size 500x58.40625 flex-container(column) children: not-inline
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+      Box <div.container> at (9,9) content-size 500x58.40625 flex-container(column) [FFC] children: not-inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,10) content-size 100x17.46875 flex-item children: inline
+        BlockContainer <div.box> at (10,10) content-size 100x17.46875 flex-item [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,10 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,29.46875) content-size 100x17.46875 flex-item children: inline
+        BlockContainer <div.box> at (10,29.46875) content-size 100x17.46875 flex-item [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,29.46875 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,48.9375) content-size 100x17.46875 flex-item children: inline
+        BlockContainer <div.box> at (10,48.9375) content-size 100x17.46875 flex-item [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,48.9375 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,68.40625) content-size 784x0 children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/flex-grow-1.txt b/Tests/LibWeb/Layout/expected/flex-grow-1.txt
index 2dcfbc1823..2de5526fb9 100644
--- a/Tests/LibWeb/Layout/expected/flex-grow-1.txt
+++ b/Tests/LibWeb/Layout/expected/flex-grow-1.txt
@@ -1,29 +1,29 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x120 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x120 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x104 children: not-inline
-      Box <div.container> at (9,9) content-size 500x102 flex-container(row) children: not-inline
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+      Box <div.container> at (9,9) content-size 500x102 flex-container(row) [FFC] children: not-inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,10) content-size 229.333343x100 flex-item children: inline
+        BlockContainer <div.box> at (10,10) content-size 229.333343x100 flex-item [BFC] children: inline
           line 0 width: 144.546875, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 17, rect: [10,10 144.546875x17.46875]
               "1 I grow the most"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (241.333343,10) content-size 164.666671x100 flex-item children: inline
+        BlockContainer <div.box> at (241.333343,10) content-size 164.666671x100 flex-item [BFC] children: inline
           line 0 width: 67.375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 8, rect: [241.333343,10 67.375x17.46875]
               "2 I grow"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (408,10) content-size 100x100 flex-item children: inline
+        BlockContainer <div.box> at (408,10) content-size 100x100 flex-item [BFC] children: inline
           line 0 width: 68, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 9, rect: [408,10 68x17.46875]
               "3 I don't"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,112) content-size 784x0 children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/flex-grow-2.txt b/Tests/LibWeb/Layout/expected/flex-grow-2.txt
index 2542329f6b..417ffbcfd2 100644
--- a/Tests/LibWeb/Layout/expected/flex-grow-2.txt
+++ b/Tests/LibWeb/Layout/expected/flex-grow-2.txt
@@ -1,29 +1,29 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x120 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x120 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x104 children: not-inline
-      Box <div.container> at (9,9) content-size 500x102 flex-container(row) children: not-inline
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+      Box <div.container> at (9,9) content-size 500x102 flex-container(row) [FFC] children: not-inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,10) content-size 82.333335x100 flex-item children: inline
+        BlockContainer <div.box> at (10,10) content-size 82.333335x100 flex-item [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,10 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (94.333335,10) content-size 164.666671x100 flex-item children: inline
+        BlockContainer <div.box> at (94.333335,10) content-size 164.666671x100 flex-item [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [94.333335,10 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (261,10) content-size 247x100 flex-item children: inline
+        BlockContainer <div.box> at (261,10) content-size 247x100 flex-item [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [261,10 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,112) content-size 784x0 children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/flex-item-auto-height-with-wrap.txt b/Tests/LibWeb/Layout/expected/flex-item-auto-height-with-wrap.txt
index 8dd4a54e86..06bbc370f6 100644
--- a/Tests/LibWeb/Layout/expected/flex-item-auto-height-with-wrap.txt
+++ b/Tests/LibWeb/Layout/expected/flex-item-auto-height-with-wrap.txt
@@ -1,11 +1,11 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x116 children: not-inline
-    Box <body.outer> at (8,8) content-size 400x100 flex-container(column) children: not-inline
-      Box <div.inner> at (8,8) content-size 400x17.46875 flex-container(row) flex-item children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 348.609375x17.46875 flex-item children: inline
+  BlockContainer <html> at (0,0) content-size 800x116 [BFC] children: not-inline
+    Box <body.outer> at (8,8) content-size 400x100 flex-container(column) [FFC] children: not-inline
+      Box <div.inner> at (8,8) content-size 400x17.46875 flex-container(row) flex-item [FFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 348.609375x17.46875 flex-item [BFC] children: inline
           line 0 width: 348.609375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 40, rect: [8,8 348.609375x17.46875]
               "The orange box should have a snug height"
           TextNode <#text>
-      BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+      BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/flex-item-on-row-with-intrinsic-aspect-ratio.txt b/Tests/LibWeb/Layout/expected/flex-item-on-row-with-intrinsic-aspect-ratio.txt
index 6da0287415..82736f3691 100644
--- a/Tests/LibWeb/Layout/expected/flex-item-on-row-with-intrinsic-aspect-ratio.txt
+++ b/Tests/LibWeb/Layout/expected/flex-item-on-row-with-intrinsic-aspect-ratio.txt
@@ -1,4 +1,4 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x200 children: not-inline
-    Box <body> at (0,0) content-size 800x200 flex-container(row) children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x200 [BFC] children: not-inline
+    Box <body> at (0,0) content-size 800x200 flex-container(row) [FFC] children: not-inline
       ImageBox <img> at (0,0) content-size 400x200 flex-item children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/flex-item-vertical-padding-relative-to-flex-container-width.txt b/Tests/LibWeb/Layout/expected/flex-item-vertical-padding-relative-to-flex-container-width.txt
index 13a17665c5..ac08d372c3 100644
--- a/Tests/LibWeb/Layout/expected/flex-item-vertical-padding-relative-to-flex-container-width.txt
+++ b/Tests/LibWeb/Layout/expected/flex-item-vertical-padding-relative-to-flex-container-width.txt
@@ -1,15 +1,15 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x30 children: not-inline
+  BlockContainer <html> at (1,1) content-size 798x30 [BFC] children: not-inline
     BlockContainer <body> at (10,10) content-size 780x12 children: not-inline
       BlockContainer <(anonymous)> at (10,10) content-size 780x0 children: inline
         TextNode <#text>
-      Box <div.flex-container> at (11,11) content-size 600x10 flex-container(row) children: not-inline
-        BlockContainer <(anonymous)> at (11,11) content-size 0x0 children: inline
+      Box <div.flex-container> at (11,11) content-size 600x10 flex-container(row) [FFC] children: not-inline
+        BlockContainer <(anonymous)> at (11,11) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.flex-item> at (12,72) content-size 27.15625x18.000007 flex-item children: inline
+        BlockContainer <div.flex-item> at (12,72) content-size 27.15625x18.000007 flex-item [BFC] children: inline
           line 0 width: 27.15625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 3, rect: [12,72 27.15625x17.46875]
               "foo"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (11,11) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (11,11) content-size 0x0 [BFC] children: inline
           TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/flex-item-with-cyclic-percentage-height.txt b/Tests/LibWeb/Layout/expected/flex-item-with-cyclic-percentage-height.txt
index 56e5352b60..e8a34a9744 100644
--- a/Tests/LibWeb/Layout/expected/flex-item-with-cyclic-percentage-height.txt
+++ b/Tests/LibWeb/Layout/expected/flex-item-with-cyclic-percentage-height.txt
@@ -1,9 +1,9 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x39.46875 children: not-inline
+  BlockContainer <html> at (1,1) content-size 798x39.46875 [BFC] children: not-inline
     BlockContainer <body> at (10,10) content-size 780x21.46875 children: not-inline
-      Box <div.flexrow> at (11,11) content-size 778x19.46875 flex-container(row) children: not-inline
-        Box <div.project> at (12,12) content-size 44.03125x17.46875 flex-container(column) flex-item children: not-inline
-          BlockContainer <(anonymous)> at (12,12) content-size 44.03125x17.46875 flex-item children: inline
+      Box <div.flexrow> at (11,11) content-size 778x19.46875 flex-container(row) [FFC] children: not-inline
+        Box <div.project> at (12,12) content-size 44.03125x17.46875 flex-container(column) flex-item [FFC] children: not-inline
+          BlockContainer <(anonymous)> at (12,12) content-size 44.03125x17.46875 flex-item [BFC] children: inline
             line 0 width: 44.03125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
               frag 0 from TextNode start: 0, length: 6, rect: [12,12 44.03125x17.46875]
                 "pillow"
diff --git a/Tests/LibWeb/Layout/expected/flex-item-with-intrinsic-aspect-ratio.txt b/Tests/LibWeb/Layout/expected/flex-item-with-intrinsic-aspect-ratio.txt
index ffac888f15..c730929e35 100644
--- a/Tests/LibWeb/Layout/expected/flex-item-with-intrinsic-aspect-ratio.txt
+++ b/Tests/LibWeb/Layout/expected/flex-item-with-intrinsic-aspect-ratio.txt
@@ -1,4 +1,4 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x200 children: not-inline
-    Box <body> at (0,0) content-size 400x200 flex-container(column) children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x200 [BFC] children: not-inline
+    Box <body> at (0,0) content-size 400x200 flex-container(column) [FFC] children: not-inline
       ImageBox <img> at (0,0) content-size 400x200 flex-item children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/flex-margin-auto-justify-content.txt b/Tests/LibWeb/Layout/expected/flex-margin-auto-justify-content.txt
index f1d4d357c4..762bfda4c9 100644
--- a/Tests/LibWeb/Layout/expected/flex-margin-auto-justify-content.txt
+++ b/Tests/LibWeb/Layout/expected/flex-margin-auto-justify-content.txt
@@ -1,18 +1,18 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x70 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x70 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x54 children: not-inline
-      Box <div.container> at (9,9) content-size 600x52 flex-container(row) children: not-inline
-        BlockContainer <div.box> at (20,10) content-size 150x50 flex-item children: inline
+      Box <div.container> at (9,9) content-size 600x52 flex-container(row) [FFC] children: not-inline
+        BlockContainer <div.box> at (20,10) content-size 150x50 flex-item [BFC] children: inline
           line 0 width: 86.359375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 11, rect: [20,10 86.359375x17.46875]
               "left margin"
           TextNode <#text>
-        BlockContainer <div.box> at (172,10) content-size 150x50 flex-item children: inline
+        BlockContainer <div.box> at (172,10) content-size 150x50 flex-item [BFC] children: inline
           line 0 width: 141.28125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 18, rect: [172,10 141.28125x17.46875]
               "follow immediately"
           TextNode <#text>
-        BlockContainer <div.box> at (458,10) content-size 150x50 flex-item children: inline
+        BlockContainer <div.box> at (458,10) content-size 150x50 flex-item [BFC] children: inline
           line 0 width: 138.296875, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 17, rect: [458,10 138.296875x17.46875]
               "over at the right"
diff --git a/Tests/LibWeb/Layout/expected/flex-row.txt b/Tests/LibWeb/Layout/expected/flex-row.txt
index 66bcaf5337..492fa9d13d 100644
--- a/Tests/LibWeb/Layout/expected/flex-row.txt
+++ b/Tests/LibWeb/Layout/expected/flex-row.txt
@@ -1,29 +1,29 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x120 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x120 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x104 children: not-inline
-      Box <div.container> at (9,9) content-size 782x102 flex-container(row) children: not-inline
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+      Box <div.container> at (9,9) content-size 782x102 flex-container(row) [FFC] children: not-inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,10) content-size 100x100 flex-item children: inline
+        BlockContainer <div.box> at (10,10) content-size 100x100 flex-item [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,10 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (112,10) content-size 100x100 flex-item children: inline
+        BlockContainer <div.box> at (112,10) content-size 100x100 flex-item [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [112,10 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (214,10) content-size 100x100 flex-item children: inline
+        BlockContainer <div.box> at (214,10) content-size 100x100 flex-item [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [214,10 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,112) content-size 784x0 children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/flex-shrink-1.txt b/Tests/LibWeb/Layout/expected/flex-shrink-1.txt
index f4c7809ed7..a59ce08afa 100644
--- a/Tests/LibWeb/Layout/expected/flex-shrink-1.txt
+++ b/Tests/LibWeb/Layout/expected/flex-shrink-1.txt
@@ -1,10 +1,10 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x120 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x120 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x104 children: not-inline
-      Box <div.container> at (9,9) content-size 250x102 flex-container(row) children: not-inline
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+      Box <div.container> at (9,9) content-size 250x102 flex-container(row) [FFC] children: not-inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,10) content-size 62.666664x100 flex-item children: inline
+        BlockContainer <div.box> at (10,10) content-size 62.666664x100 flex-item [BFC] children: inline
           line 0 width: 18.9375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 3, rect: [10,10 18.9375x17.46875]
               "1 I"
@@ -18,21 +18,21 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
             frag 0 from TextNode start: 15, length: 4, rect: [10,62 38.765625x17.46875]
               "most"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (74.666664,10) content-size 81.333328x100 flex-item children: inline
+        BlockContainer <div.box> at (74.666664,10) content-size 81.333328x100 flex-item [BFC] children: inline
           line 0 width: 78.765625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 10, rect: [74.666664,10 78.765625x17.46875]
               "2 I shrink"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (158,10) content-size 100x100 flex-item children: inline
+        BlockContainer <div.box> at (158,10) content-size 100x100 flex-item [BFC] children: inline
           line 0 width: 68, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 9, rect: [158,10 68x17.46875]
               "3 I don't"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,112) content-size 784x0 children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/flex-shrink-2.txt b/Tests/LibWeb/Layout/expected/flex-shrink-2.txt
index 74ce887671..d369a482c8 100644
--- a/Tests/LibWeb/Layout/expected/flex-shrink-2.txt
+++ b/Tests/LibWeb/Layout/expected/flex-shrink-2.txt
@@ -1,29 +1,29 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x120 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x120 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x104 children: not-inline
-      Box <div.container> at (9,9) content-size 500x102 flex-container(row) children: not-inline
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+      Box <div.container> at (9,9) content-size 500x102 flex-container(row) [FFC] children: not-inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,10) content-size 47.000030x100 flex-item children: inline
+        BlockContainer <div.box> at (10,10) content-size 47.000030x100 flex-item [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,10 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (59.000030,10) content-size 164.666671x100 flex-item children: inline
+        BlockContainer <div.box> at (59.000030,10) content-size 164.666671x100 flex-item [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [59.000030,10 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (225.666702,10) content-size 282.333312x100 flex-item children: inline
+        BlockContainer <div.box> at (225.666702,10) content-size 282.333312x100 flex-item [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [225.666702,10 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,112) content-size 784x0 children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/flex-shrink-3.txt b/Tests/LibWeb/Layout/expected/flex-shrink-3.txt
index 2408af3098..008249dcd9 100644
--- a/Tests/LibWeb/Layout/expected/flex-shrink-3.txt
+++ b/Tests/LibWeb/Layout/expected/flex-shrink-3.txt
@@ -1,29 +1,29 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x120 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x120 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x104 children: not-inline
-      Box <div.container> at (9,9) content-size 500x102 flex-container(row) children: not-inline
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+      Box <div.container> at (9,9) content-size 500x102 flex-container(row) [FFC] children: not-inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (10,10) content-size 100x100 flex-item children: inline
+        BlockContainer <div.box> at (10,10) content-size 100x100 flex-item [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [10,10 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (112,10) content-size 100x100 flex-item children: inline
+        BlockContainer <div.box> at (112,10) content-size 100x100 flex-item [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [112,10 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.box> at (214,10) content-size 100x100 flex-item children: inline
+        BlockContainer <div.box> at (214,10) content-size 100x100 flex-item [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [214,10 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (9,9) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (9,9) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,112) content-size 784x0 children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/flex/cross-size-of-item-with-box-sizing-border-box-and-nonzero-padding.txt b/Tests/LibWeb/Layout/expected/flex/cross-size-of-item-with-box-sizing-border-box-and-nonzero-padding.txt
index 0186c643a1..b3b9137fa2 100644
--- a/Tests/LibWeb/Layout/expected/flex/cross-size-of-item-with-box-sizing-border-box-and-nonzero-padding.txt
+++ b/Tests/LibWeb/Layout/expected/flex/cross-size-of-item-with-box-sizing-border-box-and-nonzero-padding.txt
@@ -1,8 +1,8 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x245.09375 children: not-inline
+  BlockContainer <html> at (1,1) content-size 798x245.09375 [BFC] children: not-inline
     BlockContainer <body> at (10,10) content-size 780x227.09375 children: not-inline
-      Box <div.outer.flex.flex-wrap> at (11,11) content-size 778x225.09375 flex-container(row) children: not-inline
-        BlockContainer <div.inner> at (12,62) content-size 776x123.09375 flex-item children: inline
+      Box <div.outer.flex.flex-wrap> at (11,11) content-size 778x225.09375 flex-container(row) [FFC] children: not-inline
+        BlockContainer <div.inner> at (12,62) content-size 776x123.09375 flex-item [BFC] children: inline
           line 0 width: 741.640625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 90, rect: [12,62 741.640625x17.46875]
               "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus interdum libero et urna"
diff --git a/Tests/LibWeb/Layout/expected/flex/flex-gap-between-items-and-lines.txt b/Tests/LibWeb/Layout/expected/flex/flex-gap-between-items-and-lines.txt
index d6b51ad414..8391fa9da5 100644
--- a/Tests/LibWeb/Layout/expected/flex/flex-gap-between-items-and-lines.txt
+++ b/Tests/LibWeb/Layout/expected/flex/flex-gap-between-items-and-lines.txt
@@ -1,12 +1,12 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x268 children: not-inline
+  BlockContainer <html> at (1,1) content-size 798x268 [BFC] children: not-inline
     BlockContainer <body> at (10,10) content-size 780x250 children: not-inline
-      Box <div.flexbox> at (11,11) content-size 100x248 flex-container(row) children: not-inline
-        BlockContainer <div> at (12,12) content-size 30x30 flex-item children: not-inline
-        BlockContainer <div> at (64,12) content-size 30x30 flex-item children: not-inline
-        BlockContainer <div> at (12,84) content-size 30x30 flex-item children: not-inline
-        BlockContainer <div> at (64,84) content-size 30x30 flex-item children: not-inline
-        BlockContainer <div> at (12,156) content-size 30x30 flex-item children: not-inline
-        BlockContainer <div> at (64,156) content-size 30x30 flex-item children: not-inline
-        BlockContainer <div> at (12,228) content-size 30x30 flex-item children: not-inline
-        BlockContainer <div> at (64,228) content-size 30x30 flex-item children: not-inline
+      Box <div.flexbox> at (11,11) content-size 100x248 flex-container(row) [FFC] children: not-inline
+        BlockContainer <div> at (12,12) content-size 30x30 flex-item [BFC] children: not-inline
+        BlockContainer <div> at (64,12) content-size 30x30 flex-item [BFC] children: not-inline
+        BlockContainer <div> at (12,84) content-size 30x30 flex-item [BFC] children: not-inline
+        BlockContainer <div> at (64,84) content-size 30x30 flex-item [BFC] children: not-inline
+        BlockContainer <div> at (12,156) content-size 30x30 flex-item [BFC] children: not-inline
+        BlockContainer <div> at (64,156) content-size 30x30 flex-item [BFC] children: not-inline
+        BlockContainer <div> at (12,228) content-size 30x30 flex-item [BFC] children: not-inline
+        BlockContainer <div> at (64,228) content-size 30x30 flex-item [BFC] children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/flex/multi-line-column-container-with-automatic-height.txt b/Tests/LibWeb/Layout/expected/flex/multi-line-column-container-with-automatic-height.txt
index 50b55e2e3c..a1b4a5a2ae 100644
--- a/Tests/LibWeb/Layout/expected/flex/multi-line-column-container-with-automatic-height.txt
+++ b/Tests/LibWeb/Layout/expected/flex/multi-line-column-container-with-automatic-height.txt
@@ -1,7 +1,7 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x176 children: not-inline
+  BlockContainer <html> at (1,1) content-size 798x176 [BFC] children: not-inline
     BlockContainer <body> at (10,10) content-size 780x158 children: not-inline
-      Box <div.flexbox> at (11,11) content-size 200x156 flex-container(column) children: not-inline
-        BlockContainer <div> at (12,12) content-size 50x50 flex-item children: not-inline
-        BlockContainer <div> at (12,64) content-size 50x50 flex-item children: not-inline
-        BlockContainer <div> at (12,116) content-size 50x50 flex-item children: not-inline
+      Box <div.flexbox> at (11,11) content-size 200x156 flex-container(column) [FFC] children: not-inline
+        BlockContainer <div> at (12,12) content-size 50x50 flex-item [BFC] children: not-inline
+        BlockContainer <div> at (12,64) content-size 50x50 flex-item [BFC] children: not-inline
+        BlockContainer <div> at (12,116) content-size 50x50 flex-item [BFC] children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/flex/percentage-flex-basis-with-indefinite-flex-container-size.txt b/Tests/LibWeb/Layout/expected/flex/percentage-flex-basis-with-indefinite-flex-container-size.txt
index df5bd83588..c4e7e039a5 100644
--- a/Tests/LibWeb/Layout/expected/flex/percentage-flex-basis-with-indefinite-flex-container-size.txt
+++ b/Tests/LibWeb/Layout/expected/flex/percentage-flex-basis-with-indefinite-flex-container-size.txt
@@ -1,7 +1,7 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x33.46875 children: not-inline
-    Box <body.outer> at (8,8) content-size 200x17.46875 flex-container(column) children: not-inline
-      BlockContainer <div.middle> at (8,8) content-size 200x17.46875 flex-item children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x33.46875 [BFC] children: not-inline
+    Box <body.outer> at (8,8) content-size 200x17.46875 flex-container(column) [FFC] children: not-inline
+      BlockContainer <div.middle> at (8,8) content-size 200x17.46875 flex-item [BFC] children: not-inline
         BlockContainer <div.inner> at (8,8) content-size 200x17.46875 children: inline
           line 0 width: 174.234375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 20, rect: [8,8 174.234375x17.46875]
diff --git a/Tests/LibWeb/Layout/expected/flex/specified-size-suggestion-with-box-sizing-border-box.txt b/Tests/LibWeb/Layout/expected/flex/specified-size-suggestion-with-box-sizing-border-box.txt
index c41d592c1c..cdaa44e7c2 100644
--- a/Tests/LibWeb/Layout/expected/flex/specified-size-suggestion-with-box-sizing-border-box.txt
+++ b/Tests/LibWeb/Layout/expected/flex/specified-size-suggestion-with-box-sizing-border-box.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x100 children: not-inline
-    Box <body> at (0,0) content-size 800x100 flex-container(row) children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x100 [BFC] children: not-inline
+    Box <body> at (0,0) content-size 800x100 flex-container(row) [FFC] children: not-inline
       ImageBox <img> at (0,0) content-size 400x100 flex-item children: not-inline
       ImageBox <img.padded> at (600,0) content-size 200x100 flex-item children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/flex/stretch-alignment-with-cross-gap.txt b/Tests/LibWeb/Layout/expected/flex/stretch-alignment-with-cross-gap.txt
index 3e244f8c6c..bce10ea2b8 100644
--- a/Tests/LibWeb/Layout/expected/flex/stretch-alignment-with-cross-gap.txt
+++ b/Tests/LibWeb/Layout/expected/flex/stretch-alignment-with-cross-gap.txt
@@ -1,10 +1,10 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x220 children: not-inline
+  BlockContainer <html> at (1,1) content-size 798x220 [BFC] children: not-inline
     BlockContainer <body> at (10,10) content-size 780x202 children: not-inline
-      Box <div.flex> at (11,11) content-size 300x200 flex-container(row) children: not-inline
-        BlockContainer <div> at (12,12) content-size 100x20 flex-item children: not-inline
-        BlockContainer <div> at (114,12) content-size 100x20 flex-item children: not-inline
-        BlockContainer <div> at (12,95.333328) content-size 100x20 flex-item children: not-inline
-        BlockContainer <div> at (114,95.333328) content-size 100x20 flex-item children: not-inline
-        BlockContainer <div> at (12,178.666656) content-size 100x20 flex-item children: not-inline
-        BlockContainer <div> at (114,178.666656) content-size 100x20 flex-item children: not-inline
+      Box <div.flex> at (11,11) content-size 300x200 flex-container(row) [FFC] children: not-inline
+        BlockContainer <div> at (12,12) content-size 100x20 flex-item [BFC] children: not-inline
+        BlockContainer <div> at (114,12) content-size 100x20 flex-item [BFC] children: not-inline
+        BlockContainer <div> at (12,95.333328) content-size 100x20 flex-item [BFC] children: not-inline
+        BlockContainer <div> at (114,95.333328) content-size 100x20 flex-item [BFC] children: not-inline
+        BlockContainer <div> at (12,178.666656) content-size 100x20 flex-item [BFC] children: not-inline
+        BlockContainer <div> at (114,178.666656) content-size 100x20 flex-item [BFC] children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/grid/auto-fill.txt b/Tests/LibWeb/Layout/expected/grid/auto-fill.txt
index 09f5a41d7d..1fed151e66 100644
--- a/Tests/LibWeb/Layout/expected/grid/auto-fill.txt
+++ b/Tests/LibWeb/Layout/expected/grid/auto-fill.txt
@@ -1,27 +1,27 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x33.46875 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x33.46875 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x17.46875 children: not-inline
-      Box <div.grid-container> at (8,8) content-size 784x17.46875 children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,8) content-size 784x17.46875 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,8) content-size 261.333343x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,8) content-size 261.333343x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,8 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (269.333343,8) content-size 261.333343x17.46875 children: inline
+        BlockContainer <div.grid-item> at (269.333343,8) content-size 261.333343x17.46875 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [269.333343,8 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (530.666687,8) content-size 261.333312x17.46875 children: inline
+        BlockContainer <div.grid-item> at (530.666687,8) content-size 261.333312x17.46875 [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [530.666687,8 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/grid/auto-fit.txt b/Tests/LibWeb/Layout/expected/grid/auto-fit.txt
index 09f5a41d7d..1fed151e66 100644
--- a/Tests/LibWeb/Layout/expected/grid/auto-fit.txt
+++ b/Tests/LibWeb/Layout/expected/grid/auto-fit.txt
@@ -1,27 +1,27 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x33.46875 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x33.46875 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x17.46875 children: not-inline
-      Box <div.grid-container> at (8,8) content-size 784x17.46875 children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,8) content-size 784x17.46875 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,8) content-size 261.333343x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,8) content-size 261.333343x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,8 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (269.333343,8) content-size 261.333343x17.46875 children: inline
+        BlockContainer <div.grid-item> at (269.333343,8) content-size 261.333343x17.46875 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [269.333343,8 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (530.666687,8) content-size 261.333312x17.46875 children: inline
+        BlockContainer <div.grid-item> at (530.666687,8) content-size 261.333312x17.46875 [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [530.666687,8 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/grid/basic.txt b/Tests/LibWeb/Layout/expected/grid/basic.txt
index f81bd57e1a..d288af210c 100644
--- a/Tests/LibWeb/Layout/expected/grid/basic.txt
+++ b/Tests/LibWeb/Layout/expected/grid/basic.txt
@@ -1,34 +1,34 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x50.9375 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x50.9375 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x34.9375 children: not-inline
-      Box <div.grid-container> at (8,8) content-size 784x34.9375 children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,8) content-size 784x34.9375 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,8) content-size 392.140625x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,8) content-size 392.140625x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,8 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (400.140625,8) content-size 392x17.46875 children: inline
+        BlockContainer <div.grid-item> at (400.140625,8) content-size 392x17.46875 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [400.140625,8 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,25.46875) content-size 392.140625x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,25.46875) content-size 392.140625x17.46875 [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,25.46875 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (400.140625,25.46875) content-size 392x17.46875 children: inline
+        BlockContainer <div.grid-item> at (400.140625,25.46875) content-size 392x17.46875 [BFC] children: inline
           line 0 width: 7.75, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [400.140625,25.46875 7.75x17.46875]
               "4"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/grid/borders.txt b/Tests/LibWeb/Layout/expected/grid/borders.txt
index cec9df1629..723df0a461 100644
--- a/Tests/LibWeb/Layout/expected/grid/borders.txt
+++ b/Tests/LibWeb/Layout/expected/grid/borders.txt
@@ -1,164 +1,164 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x444.28125 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x444.28125 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x428.28125 children: not-inline
-      Box <div.grid-container> at (8,8) content-size 784x74.9375 children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,8) content-size 784x74.9375 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (18,18) content-size 372.140625x17.46875 children: inline
+        BlockContainer <div.grid-item> at (18,18) content-size 372.140625x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [18,18 6.34375x17.46875]
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           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (410.140625,18) content-size 372x17.46875 children: inline
+        BlockContainer <div.grid-item> at (410.140625,18) content-size 372x17.46875 [BFC] children: inline
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             frag 0 from TextNode start: 0, length: 1, rect: [410.140625,18 8.8125x17.46875]
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           TextNode <#text>
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+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (18,55.46875) content-size 372.140625x17.46875 children: inline
+        BlockContainer <div.grid-item> at (18,55.46875) content-size 372.140625x17.46875 [BFC] children: inline
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             frag 0 from TextNode start: 0, length: 1, rect: [18,55.46875 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (410.140625,55.46875) content-size 372x17.46875 children: inline
+        BlockContainer <div.grid-item> at (410.140625,55.46875) content-size 372x17.46875 [BFC] children: inline
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             frag 0 from TextNode start: 0, length: 1, rect: [410.140625,55.46875 7.75x17.46875]
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           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,82.9375) content-size 784x0 children: inline
         TextNode <#text>
-      Box <div.grid-container> at (8,82.9375) content-size 784x107.46875 children: not-inline
-        BlockContainer <(anonymous)> at (8,82.9375) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,82.9375) content-size 784x107.46875 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,82.9375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (18,92.9375) content-size 372.140625x50 children: inline
+        BlockContainer <div.grid-item> at (18,92.9375) content-size 372.140625x50 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [18,92.9375 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,82.9375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,82.9375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (410.140625,92.9375) content-size 372x50 children: inline
+        BlockContainer <div.grid-item> at (410.140625,92.9375) content-size 372x50 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [410.140625,92.9375 8.8125x17.46875]
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           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,82.9375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,82.9375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (18,162.9375) content-size 372.140625x17.46875 children: inline
+        BlockContainer <div.grid-item> at (18,162.9375) content-size 372.140625x17.46875 [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [18,162.9375 9.09375x17.46875]
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           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,82.9375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,82.9375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (410.140625,162.9375) content-size 372x17.46875 children: inline
+        BlockContainer <div.grid-item> at (410.140625,162.9375) content-size 372x17.46875 [BFC] children: inline
           line 0 width: 7.75, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [410.140625,162.9375 7.75x17.46875]
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           TextNode <#text>
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+        BlockContainer <(anonymous)> at (8,82.9375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,190.40625) content-size 784x0 children: inline
         TextNode <#text>
-      Box <div.grid-container> at (8,190.40625) content-size 784x84.9375 children: not-inline
-        BlockContainer <(anonymous)> at (8,190.40625) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,190.40625) content-size 784x84.9375 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,190.40625) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (18,200.40625) content-size 347.140625x17.46875 children: inline
+        BlockContainer <div.grid-item> at (18,200.40625) content-size 347.140625x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [18,200.40625 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,190.40625) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,190.40625) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (435.140625,200.40625) content-size 347x17.46875 children: inline
+        BlockContainer <div.grid-item> at (435.140625,200.40625) content-size 347x17.46875 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [435.140625,200.40625 8.8125x17.46875]
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           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,190.40625) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,190.40625) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (18,247.875) content-size 347.140625x17.46875 children: inline
+        BlockContainer <div.grid-item> at (18,247.875) content-size 347.140625x17.46875 [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [18,247.875 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,190.40625) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,190.40625) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (435.140625,247.875) content-size 347x17.46875 children: inline
+        BlockContainer <div.grid-item> at (435.140625,247.875) content-size 347x17.46875 [BFC] children: inline
           line 0 width: 7.75, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [435.140625,247.875 7.75x17.46875]
               "4"
           TextNode <#text>
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+        BlockContainer <(anonymous)> at (8,190.40625) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,275.34375) content-size 784x0 children: inline
         TextNode <#text>
-      Box <div.grid-container> at (8,275.34375) content-size 784x90.9375 children: not-inline
-        BlockContainer <(anonymous)> at (8,275.34375) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,275.34375) content-size 784x90.9375 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,275.34375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (445.934356,285.34375) content-size 337.300018x17.46875 children: inline
+        BlockContainer <div.grid-item> at (445.934356,285.34375) content-size 337.300018x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [445.934356,285.34375 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,275.34375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,275.34375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (18,338.8125) content-size 338.534362x17.46875 children: inline
+        BlockContainer <div.grid-item> at (18,338.8125) content-size 338.534362x17.46875 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [18,338.8125 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,275.34375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,275.34375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,366.28125) content-size 784x0 children: inline
         TextNode <#text>
-      Box <div.grid-container> at (8,366.28125) content-size 784x50 children: not-inline
-        BlockContainer <(anonymous)> at (8,366.28125) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,366.28125) content-size 784x50 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,366.28125) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (18,376.28125) content-size 280x5 children: inline
+        BlockContainer <div.grid-item> at (18,376.28125) content-size 280x5 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [18,376.28125 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,366.28125) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,366.28125) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (318,376.28125) content-size 280x5 children: inline
+        BlockContainer <div.grid-item> at (318,376.28125) content-size 280x5 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [318,376.28125 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,366.28125) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,366.28125) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (18,401.28125) content-size 280x5 children: inline
+        BlockContainer <div.grid-item> at (18,401.28125) content-size 280x5 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [18,401.28125 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,366.28125) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,366.28125) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (318,401.28125) content-size 280x5 children: inline
+        BlockContainer <div.grid-item> at (318,401.28125) content-size 280x5 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [318,401.28125 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,366.28125) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,366.28125) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,416.28125) content-size 784x0 children: inline
         TextNode <#text>
-      Box <div.grid-container> at (8,416.28125) content-size 784x20 children: not-inline
-        BlockContainer <(anonymous)> at (8,416.28125) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,416.28125) content-size 784x20 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,416.28125) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (18,426.28125) content-size 764x0 children: inline
+        BlockContainer <div.grid-item> at (18,426.28125) content-size 764x0 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [18,426.28125 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,416.28125) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,416.28125) content-size 0x0 [BFC] children: inline
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diff --git a/Tests/LibWeb/Layout/expected/grid/different-column-sizes.txt b/Tests/LibWeb/Layout/expected/grid/different-column-sizes.txt
index 49d3b9ab9e..e8bd5b789c 100644
--- a/Tests/LibWeb/Layout/expected/grid/different-column-sizes.txt
+++ b/Tests/LibWeb/Layout/expected/grid/different-column-sizes.txt
@@ -1,34 +1,34 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x50.9375 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x50.9375 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x34.9375 children: not-inline
-      Box <div.grid-container> at (8,8) content-size 784x34.9375 children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,8) content-size 784x34.9375 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,8) content-size 50x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,8) content-size 50x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,8 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (58,8) content-size 392x17.46875 children: inline
+        BlockContainer <div.grid-item> at (58,8) content-size 392x17.46875 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [58,8 8.8125x17.46875]
               "2"
           TextNode <#text>
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+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,25.46875) content-size 50x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,25.46875) content-size 50x17.46875 [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,25.46875 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (58,25.46875) content-size 392x17.46875 children: inline
+        BlockContainer <div.grid-item> at (58,25.46875) content-size 392x17.46875 [BFC] children: inline
           line 0 width: 7.75, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [58,25.46875 7.75x17.46875]
               "4"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/grid/gap.txt b/Tests/LibWeb/Layout/expected/grid/gap.txt
index e199efc197..646b0cb779 100644
--- a/Tests/LibWeb/Layout/expected/grid/gap.txt
+++ b/Tests/LibWeb/Layout/expected/grid/gap.txt
@@ -1,102 +1,102 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x166.8125 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x166.8125 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x150.8125 children: not-inline
-      Box <div.grid-container> at (8,8) content-size 784x44.9375 children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,8) content-size 784x44.9375 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,8) content-size 367.140625x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,8) content-size 367.140625x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,8 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (425.140625,8) content-size 367x17.46875 children: inline
+        BlockContainer <div.grid-item> at (425.140625,8) content-size 367x17.46875 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [425.140625,8 8.8125x17.46875]
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           TextNode <#text>
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+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,35.46875) content-size 367.140625x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,35.46875) content-size 367.140625x17.46875 [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,35.46875 9.09375x17.46875]
               "3"
           TextNode <#text>
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+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (425.140625,35.46875) content-size 367x17.46875 children: inline
+        BlockContainer <div.grid-item> at (425.140625,35.46875) content-size 367x17.46875 [BFC] children: inline
           line 0 width: 7.75, height: 17.46875, bottom: 17.46875, baseline: 13.53125
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           TextNode <#text>
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+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,52.9375) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
-      Box <div.grid-container> at (8,52.9375) content-size 784x50.9375 children: not-inline
-        BlockContainer <(anonymous)> at (8,52.9375) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,52.9375) content-size 784x50.9375 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,52.9375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (435.934356,52.9375) content-size 357.300018x17.46875 children: inline
+        BlockContainer <div.grid-item> at (435.934356,52.9375) content-size 357.300018x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [435.934356,52.9375 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,52.9375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,52.9375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,86.40625) content-size 358.534362x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,86.40625) content-size 358.534362x17.46875 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,86.40625 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,52.9375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,52.9375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,103.875) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
         TextNode <#text>
-      Box <div.grid-container> at (8,103.875) content-size 784x17.46875 children: not-inline
-        BlockContainer <(anonymous)> at (8,103.875) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,103.875) content-size 784x17.46875 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,103.875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (408,103.875) content-size 384x17.46875 children: inline
+        BlockContainer <div.grid-item> at (408,103.875) content-size 384x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [408,103.875 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,103.875) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,103.875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,121.34375) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
         TextNode <#text>
-      Box <div.grid-container> at (8,121.34375) content-size 784x20 children: not-inline
-        BlockContainer <(anonymous)> at (8,121.34375) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,121.34375) content-size 784x20 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,121.34375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (408,121.34375) content-size 384x20 children: inline
+        BlockContainer <div.grid-item> at (408,121.34375) content-size 384x20 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [408,121.34375 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,121.34375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,121.34375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,141.34375) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
-      Box <div.grid-container.with-border> at (8,141.34375) content-size 784x17.46875 children: not-inline
-        BlockContainer <(anonymous)> at (8,141.34375) content-size 0x0 children: inline
+      Box <div.grid-container.with-border> at (8,141.34375) content-size 784x17.46875 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,141.34375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item.with-border> at (8,141.34375) content-size 387x17.46875 children: inline
+        BlockContainer <div.grid-item.with-border> at (8,141.34375) content-size 387x17.46875 [BFC] children: inline
           line 0 width: 104.875, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 14, rect: [8,141.34375 104.875x17.46875]
               "left side text"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,141.34375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,141.34375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item.with-border> at (405,141.34375) content-size 387x17.46875 children: inline
+        BlockContainer <div.grid-item.with-border> at (405,141.34375) content-size 387x17.46875 [BFC] children: inline
           line 0 width: 363.203125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 47, rect: [405,141.34375 363.203125x17.46875]
               "right side text right side text right side text"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,141.34375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,141.34375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/grid/grid-template.txt b/Tests/LibWeb/Layout/expected/grid/grid-template.txt
index 10644bbde2..24fed61021 100644
--- a/Tests/LibWeb/Layout/expected/grid/grid-template.txt
+++ b/Tests/LibWeb/Layout/expected/grid/grid-template.txt
@@ -1,54 +1,54 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x216 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x216 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x200 children: not-inline
-      Box <div.mw-page-container-inner> at (8,8) content-size 784x0 children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+      Box <div.mw-page-container-inner> at (8,8) content-size 784x0 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.vector-main-menu-container> at (8,8) content-size 196x0 children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <div.vector-main-menu-container> at (8,8) content-size 196x0 [BFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.vector-sitenotice-container> at (8,8) content-size 784x0 children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <div.vector-sitenotice-container> at (8,8) content-size 784x0 [BFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.mw-content-container> at (204,8) content-size 588x0 children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <div.mw-content-container> at (204,8) content-size 588x0 [BFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.mw-footer-container> at (8,8) content-size 784x0 children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <div.mw-footer-container> at (8,8) content-size 784x0 [BFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,8) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
-      Box <section#page> at (8,8) content-size 784x200 children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+      Box <section#page> at (8,8) content-size 784x200 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <header> at (8,8) content-size 784x30 children: inline
+        BlockContainer <header> at (8,8) content-size 784x30 [BFC] children: inline
           line 0 width: 55.703125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 6, rect: [8,8 55.703125x17.46875]
               "Header"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <nav> at (8,38) content-size 120x170 children: inline
+        BlockContainer <nav> at (8,38) content-size 120x170 [BFC] children: inline
           line 0 width: 80.6875, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 10, rect: [8,38 80.6875x17.46875]
               "Navigation"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <main> at (128,38) content-size 664x140 children: inline
+        BlockContainer <main> at (128,38) content-size 664x140 [BFC] children: inline
           line 0 width: 79.515625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 9, rect: [128,38 79.515625x17.46875]
               "Main area"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <footer> at (128,178) content-size 664x30 children: inline
+        BlockContainer <footer> at (128,178) content-size 664x30 [BFC] children: inline
           line 0 width: 57.671875, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 6, rect: [128,178 57.671875x17.46875]
               "Footer"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,208) content-size 784x0 children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/grid/image-in-grid.txt b/Tests/LibWeb/Layout/expected/grid/image-in-grid.txt
index a16f899a64..2d9087407c 100644
--- a/Tests/LibWeb/Layout/expected/grid/image-in-grid.txt
+++ b/Tests/LibWeb/Layout/expected/grid/image-in-grid.txt
@@ -1,14 +1,14 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x40 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x40 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x24 children: not-inline
-      Box <div.grid-container> at (8,8) content-size 784x24 children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,8) content-size 784x24 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.wrapper> at (8,8) content-size 64x24 children: inline
+        BlockContainer <div.wrapper> at (8,8) content-size 64x24 [BFC] children: inline
           line 0 width: 64, height: 24, bottom: 24, baseline: 24
             frag 0 from ImageBox start: 0, length: 0, rect: [8,8 64x24]
           TextNode <#text>
           ImageBox <img> at (8,8) content-size 64x24 children: not-inline
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/grid/intrinsic-sized-column.txt b/Tests/LibWeb/Layout/expected/grid/intrinsic-sized-column.txt
index 4ce9fb924e..f38e75368d 100644
--- a/Tests/LibWeb/Layout/expected/grid/intrinsic-sized-column.txt
+++ b/Tests/LibWeb/Layout/expected/grid/intrinsic-sized-column.txt
@@ -1,13 +1,13 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x35.46875 children: inline
+  BlockContainer <html> at (0,0) content-size 800x35.46875 [BFC] children: inline
     TextNode <#text>
-    BlockContainer <body> at (8,8) content-size 0x19.46875 floating children: not-inline
+    BlockContainer <body> at (8,8) content-size 0x19.46875 floating [BFC] children: not-inline
       BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
         TextNode <#text>
-      Box <div.grid> at (8,8) content-size 0x19.46875 children: not-inline
-        BlockContainer <(anonymous)>  children: inline
+      Box <div.grid> at (8,8) content-size 0x19.46875 [GFC] children: not-inline
+        BlockContainer <(anonymous)>  [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.whee> at (9,9) content-size 18x17.46875 children: inline
+        BlockContainer <div.whee> at (9,9) content-size 18x17.46875 [BFC] children: inline
           line 0 width: 37.953125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 4, rect: [9,9 37.953125x17.46875]
               "whee"
diff --git a/Tests/LibWeb/Layout/expected/grid/intrinsic-sized-grid.txt b/Tests/LibWeb/Layout/expected/grid/intrinsic-sized-grid.txt
index ad400613e9..6769ed3a4a 100644
--- a/Tests/LibWeb/Layout/expected/grid/intrinsic-sized-grid.txt
+++ b/Tests/LibWeb/Layout/expected/grid/intrinsic-sized-grid.txt
@@ -1,8 +1,8 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x39.46875 children: not-inline
-    BlockContainer <body> at (10,10) content-size 2x21.46875 floating children: not-inline
-      Box <div.grid> at (11,11) content-size 0x19.46875 children: not-inline
-        BlockContainer <div.whee> at (12,12) content-size 35.953125x17.46875 children: inline
+  BlockContainer <html> at (1,1) content-size 798x39.46875 [BFC] children: not-inline
+    BlockContainer <body> at (10,10) content-size 2x21.46875 floating [BFC] children: not-inline
+      Box <div.grid> at (11,11) content-size 0x19.46875 [GFC] children: not-inline
+        BlockContainer <div.whee> at (12,12) content-size 35.953125x17.46875 [BFC] children: inline
           line 0 width: 37.953125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 4, rect: [12,12 37.953125x17.46875]
               "whee"
diff --git a/Tests/LibWeb/Layout/expected/grid/min-max-content.txt b/Tests/LibWeb/Layout/expected/grid/min-max-content.txt
index cd41b7000d..666d41a742 100644
--- a/Tests/LibWeb/Layout/expected/grid/min-max-content.txt
+++ b/Tests/LibWeb/Layout/expected/grid/min-max-content.txt
@@ -1,27 +1,27 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x33.46875 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x33.46875 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x17.46875 children: not-inline
-      Box <div.grid-container> at (8,8) content-size 784x17.46875 children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,8) content-size 784x17.46875 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,8) content-size 93.765625x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,8) content-size 93.765625x17.46875 [BFC] children: inline
           line 0 width: 93.765625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 11, rect: [8,8 93.765625x17.46875]
               "min-content"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (101.765625,8) content-size 98.640625x17.46875 children: inline
+        BlockContainer <div.grid-item> at (101.765625,8) content-size 98.640625x17.46875 [BFC] children: inline
           line 0 width: 98.640625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 11, rect: [101.765625,8 98.640625x17.46875]
               "max-content"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (200.40625,8) content-size 591.59375x17.46875 children: inline
+        BlockContainer <div.grid-item> at (200.40625,8) content-size 591.59375x17.46875 [BFC] children: inline
           line 0 width: 21.609375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 3, rect: [200.40625,8 21.609375x17.46875]
               "1fr"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/grid/minmax.txt b/Tests/LibWeb/Layout/expected/grid/minmax.txt
index 3935b3cc0e..f12d0461cc 100644
--- a/Tests/LibWeb/Layout/expected/grid/minmax.txt
+++ b/Tests/LibWeb/Layout/expected/grid/minmax.txt
@@ -1,168 +1,168 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x288.28125 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x288.28125 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x272.28125 children: not-inline
-      Box <div.grid-container> at (8,8) content-size 784x17.46875 children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,8) content-size 784x17.46875 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,8) content-size 300x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,8) content-size 300x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,8 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (308,8) content-size 300x17.46875 children: inline
+        BlockContainer <div.grid-item> at (308,8) content-size 300x17.46875 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [308,8 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,25.46875) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
-      Box <div.grid-container> at (8,25.46875) content-size 784x100 children: not-inline
-        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,25.46875) content-size 784x100 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,25.46875) content-size 300x50 children: inline
+        BlockContainer <div.grid-item> at (8,25.46875) content-size 300x50 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,25.46875 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (308,25.46875) content-size 300x50 children: inline
+        BlockContainer <div.grid-item> at (308,25.46875) content-size 300x50 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [308,25.46875 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,125.46875) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
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-        BlockContainer <(anonymous)> at (8,125.46875) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,125.46875) content-size 784x34.9375 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,125.46875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,125.46875) content-size 784x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,125.46875) content-size 784x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,125.46875 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,125.46875) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,125.46875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,142.9375) content-size 784x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,142.9375) content-size 784x17.46875 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,142.9375 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,125.46875) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,125.46875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,160.40625) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
-      Box <div.grid-container> at (8,160.40625) content-size 784x34.9375 children: not-inline
-        BlockContainer <(anonymous)> at (8,160.40625) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,160.40625) content-size 784x34.9375 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,160.40625) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,160.40625) content-size 784x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,160.40625) content-size 784x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,160.40625 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,160.40625) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,160.40625) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,177.875) content-size 784x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,177.875) content-size 784x17.46875 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,177.875 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,160.40625) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,160.40625) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,195.34375) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
-      Box <div.grid-container> at (8,195.34375) content-size 784x50 children: not-inline
-        BlockContainer <(anonymous)> at (8,195.34375) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,195.34375) content-size 784x50 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,195.34375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,195.34375) content-size 300x25 children: inline
+        BlockContainer <div.grid-item> at (8,195.34375) content-size 300x25 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,195.34375 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,195.34375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,195.34375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (308,195.34375) content-size 300x25 children: inline
+        BlockContainer <div.grid-item> at (308,195.34375) content-size 300x25 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [308,195.34375 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,195.34375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,195.34375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,220.34375) content-size 300x25 children: inline
+        BlockContainer <div.grid-item> at (8,220.34375) content-size 300x25 [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,220.34375 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,195.34375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,195.34375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (308,220.34375) content-size 300x25 children: inline
+        BlockContainer <div.grid-item> at (308,220.34375) content-size 300x25 [BFC] children: inline
           line 0 width: 7.75, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [308,220.34375 7.75x17.46875]
               "4"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,195.34375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,195.34375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,245.34375) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
-      Box <div.grid-container> at (8,245.34375) content-size 784x17.46875 children: not-inline
-        BlockContainer <(anonymous)> at (8,245.34375) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,245.34375) content-size 784x17.46875 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,245.34375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,245.34375) content-size 261.333343x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,245.34375) content-size 261.333343x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,245.34375 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,245.34375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,245.34375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (269.333343,245.34375) content-size 261.333343x17.46875 children: inline
+        BlockContainer <div.grid-item> at (269.333343,245.34375) content-size 261.333343x17.46875 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [269.333343,245.34375 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,245.34375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,245.34375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (530.666687,245.34375) content-size 261.333312x17.46875 children: inline
+        BlockContainer <div.grid-item> at (530.666687,245.34375) content-size 261.333312x17.46875 [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [530.666687,245.34375 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,245.34375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,245.34375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,262.8125) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
-      Box <div.grid-container> at (8,262.8125) content-size 784x17.46875 children: not-inline
-        BlockContainer <(anonymous)> at (8,262.8125) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,262.8125) content-size 784x17.46875 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,262.8125) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,262.8125) content-size 56.218711x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,262.8125) content-size 56.218711x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,262.8125 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,262.8125) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,262.8125) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (64.218711,262.8125) content-size 671.5625x17.46875 children: inline
+        BlockContainer <div.grid-item> at (64.218711,262.8125) content-size 671.5625x17.46875 [BFC] children: inline
           line 0 width: 125.265625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 15, rect: [64.218711,262.8125 125.265625x17.46875]
               "Article content"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,262.8125) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,262.8125) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (735.781188,262.8125) content-size 56.218688x17.46875 children: inline
+        BlockContainer <div.grid-item> at (735.781188,262.8125) content-size 56.218688x17.46875 [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [735.781188,262.8125 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,262.8125) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,262.8125) content-size 0x0 [BFC] children: inline
           TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/grid/named-tracks.txt b/Tests/LibWeb/Layout/expected/grid/named-tracks.txt
index 174763be8d..c25fdf612d 100644
--- a/Tests/LibWeb/Layout/expected/grid/named-tracks.txt
+++ b/Tests/LibWeb/Layout/expected/grid/named-tracks.txt
@@ -1,90 +1,90 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x143.40625 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x143.40625 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x127.40625 children: not-inline
-      Box <div.grid-container> at (8,8) content-size 784x17.46875 children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,8) content-size 784x17.46875 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,8) content-size 392x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,8) content-size 392x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,8 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (400,8) content-size 393.234375x17.46875 children: inline
+        BlockContainer <div.grid-item> at (400,8) content-size 393.234375x17.46875 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [400,8 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,25.46875) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
         TextNode <#text>
-      Box <div.grid-container> at (8,25.46875) content-size 784x75 children: not-inline
-        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,25.46875) content-size 784x75 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,25.46875) content-size 261.333343x75 children: inline
+        BlockContainer <div.grid-item> at (8,25.46875) content-size 261.333343x75 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,25.46875 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (530.666687,25.46875) content-size 261.333312x50 children: inline
+        BlockContainer <div.grid-item> at (530.666687,25.46875) content-size 261.333312x50 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [530.666687,25.46875 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (269.333343,25.46875) content-size 261.333343x25 children: inline
+        BlockContainer <div.grid-item> at (269.333343,25.46875) content-size 261.333343x25 [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [269.333343,25.46875 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (269.333343,75.46875) content-size 522.666625x25 children: inline
+        BlockContainer <div.grid-item> at (269.333343,75.46875) content-size 522.666625x25 [BFC] children: inline
           line 0 width: 7.75, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [269.333343,75.46875 7.75x17.46875]
               "4"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,100.46875) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
         TextNode <#text>
-      Box <div.grid-container> at (8,100.46875) content-size 784x34.9375 children: not-inline
-        BlockContainer <(anonymous)> at (8,100.46875) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,100.46875) content-size 784x34.9375 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,100.46875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (58,100.46875) content-size 100x17.46875 children: inline
+        BlockContainer <div.grid-item> at (58,100.46875) content-size 100x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [58,100.46875 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,100.46875) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,100.46875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (158,100.46875) content-size 50x17.46875 children: inline
+        BlockContainer <div.grid-item> at (158,100.46875) content-size 50x17.46875 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [158,100.46875 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,100.46875) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,100.46875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (208,100.46875) content-size 100x17.46875 children: inline
+        BlockContainer <div.grid-item> at (208,100.46875) content-size 100x17.46875 [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [208,100.46875 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,100.46875) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,100.46875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,117.9375) content-size 50x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,117.9375) content-size 50x17.46875 [BFC] children: inline
           line 0 width: 7.75, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,117.9375 7.75x17.46875]
               "4"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,100.46875) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,100.46875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/grid/positions-and-spans.txt b/Tests/LibWeb/Layout/expected/grid/positions-and-spans.txt
index f3a5bfb7d4..870a6e7b32 100644
--- a/Tests/LibWeb/Layout/expected/grid/positions-and-spans.txt
+++ b/Tests/LibWeb/Layout/expected/grid/positions-and-spans.txt
@@ -1,83 +1,83 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x185.875 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x185.875 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x169.875 children: not-inline
-      Box <div.grid-container> at (8,8) content-size 784x17.46875 children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,8) content-size 784x17.46875 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,8) content-size 522.666748x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,8) content-size 522.666748x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,8 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (530.666748,8) content-size 261.333496x17.46875 children: inline
+        BlockContainer <div.grid-item> at (530.666748,8) content-size 261.333496x17.46875 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [530.666748,8 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,25.46875) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
         TextNode <#text>
-      Box <div.grid-container> at (8,25.46875) content-size 784x17.46875 children: not-inline
-        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,25.46875) content-size 784x17.46875 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,25.46875) content-size 261.333374x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,25.46875) content-size 261.333374x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,25.46875 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (269.333374,25.46875) content-size 522.66687x17.46875 children: inline
+        BlockContainer <div.grid-item> at (269.333374,25.46875) content-size 522.66687x17.46875 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [269.333374,25.46875 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,25.46875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,42.9375) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
         TextNode <#text>
-      Box <div.grid-container> at (8,42.9375) content-size 784x100 children: not-inline
-        BlockContainer <(anonymous)> at (8,42.9375) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,42.9375) content-size 784x100 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,42.9375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,42.9375) content-size 784x40 children: inline
+        BlockContainer <div.grid-item> at (8,42.9375) content-size 784x40 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,42.9375 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,42.9375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,42.9375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,82.9375) content-size 784x60 children: inline
+        BlockContainer <div.grid-item> at (8,82.9375) content-size 784x60 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,82.9375 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,42.9375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,42.9375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,142.9375) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
         TextNode <#text>
-      Box <div.grid-container> at (8,142.9375) content-size 784x34.9375 children: not-inline
-        BlockContainer <(anonymous)> at (8,142.9375) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,142.9375) content-size 784x34.9375 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,142.9375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,142.9375) content-size 784x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,142.9375) content-size 784x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,142.9375 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,142.9375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,142.9375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,160.40625) content-size 392x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,160.40625) content-size 392x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,160.40625 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,142.9375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,142.9375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/grid/repeat.txt b/Tests/LibWeb/Layout/expected/grid/repeat.txt
index f6bbc653b9..78bfccd5af 100644
--- a/Tests/LibWeb/Layout/expected/grid/repeat.txt
+++ b/Tests/LibWeb/Layout/expected/grid/repeat.txt
@@ -1,83 +1,83 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x233.46875 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x233.46875 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x217.46875 children: not-inline
-      Box <div.grid-container> at (8,8) content-size 784x200 children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,8) content-size 784x200 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,8) content-size 392x200 children: inline
+        BlockContainer <div.grid-item> at (8,8) content-size 392x200 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,8 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (400,8) content-size 392x100 children: inline
+        BlockContainer <div.grid-item> at (400,8) content-size 392x100 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [400,8 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (400,108) content-size 196x50 children: inline
+        BlockContainer <div.grid-item> at (400,108) content-size 196x50 [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [400,108 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (596,108) content-size 196x50 children: inline
+        BlockContainer <div.grid-item> at (596,108) content-size 196x50 [BFC] children: inline
           line 0 width: 7.75, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [596,108 7.75x17.46875]
               "4"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (400,158) content-size 196x50 children: inline
+        BlockContainer <div.grid-item> at (400,158) content-size 196x50 [BFC] children: inline
           line 0 width: 8.453125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [400,158 8.453125x17.46875]
               "5"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (596,158) content-size 196x50 children: inline
+        BlockContainer <div.grid-item> at (596,158) content-size 196x50 [BFC] children: inline
           line 0 width: 8.734375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [596,158 8.734375x17.46875]
               "6"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,208) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
         TextNode <#text>
-      Box <div.grid-container> at (8,208) content-size 784x17.46875 children: not-inline
-        BlockContainer <(anonymous)> at (8,208) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,208) content-size 784x17.46875 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,208) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,208) content-size 50x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,208) content-size 50x17.46875 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,208 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,208) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,208) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (58,208) content-size 50x17.46875 children: inline
+        BlockContainer <div.grid-item> at (58,208) content-size 50x17.46875 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [58,208 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,208) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,208) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (108,208) content-size 100x17.46875 children: inline
+        BlockContainer <div.grid-item> at (108,208) content-size 100x17.46875 [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [108,208 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,208) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,208) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (208,208) content-size 100x17.46875 children: inline
+        BlockContainer <div.grid-item> at (208,208) content-size 100x17.46875 [BFC] children: inline
           line 0 width: 7.75, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [208,208 7.75x17.46875]
               "4"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,208) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,208) content-size 0x0 [BFC] children: inline
           TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/grid/row-height.txt b/Tests/LibWeb/Layout/expected/grid/row-height.txt
index caa97fd2e4..7991654c97 100644
--- a/Tests/LibWeb/Layout/expected/grid/row-height.txt
+++ b/Tests/LibWeb/Layout/expected/grid/row-height.txt
@@ -1,34 +1,34 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x83.46875 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x83.46875 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x67.46875 children: not-inline
-      Box <div.grid-container> at (8,8) content-size 784x67.46875 children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,8) content-size 784x67.46875 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,8) content-size 392.140625x50 children: inline
+        BlockContainer <div.grid-item> at (8,8) content-size 392.140625x50 [BFC] children: inline
           line 0 width: 6.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,8 6.34375x17.46875]
               "1"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (400.140625,8) content-size 392x50 children: inline
+        BlockContainer <div.grid-item> at (400.140625,8) content-size 392x50 [BFC] children: inline
           line 0 width: 8.8125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [400.140625,8 8.8125x17.46875]
               "2"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,58) content-size 392.140625x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,58) content-size 392.140625x17.46875 [BFC] children: inline
           line 0 width: 9.09375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [8,58 9.09375x17.46875]
               "3"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (400.140625,58) content-size 392x17.46875 children: inline
+        BlockContainer <div.grid-item> at (400.140625,58) content-size 392x17.46875 [BFC] children: inline
           line 0 width: 7.75, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 1, rect: [400.140625,58 7.75x17.46875]
               "4"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/grid/template-areas.txt b/Tests/LibWeb/Layout/expected/grid/template-areas.txt
index b4fa315ca8..0eb7a39239 100644
--- a/Tests/LibWeb/Layout/expected/grid/template-areas.txt
+++ b/Tests/LibWeb/Layout/expected/grid/template-areas.txt
@@ -1,83 +1,83 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x120.8125 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x120.8125 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x104.8125 children: not-inline
-      Box <div.grid-container> at (8,8) content-size 784x34.9375 children: not-inline
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,8) content-size 784x34.9375 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div> at (400,25.46875) content-size 392x17.46875 children: inline
+        BlockContainer <div> at (400,25.46875) content-size 392x17.46875 [BFC] children: inline
           line 0 width: 99.703125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 1, length: 12, rect: [400,25.46875 99.703125x17.46875]
               "right-bottom"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div> at (8,8) content-size 392x34.9375 children: inline
+        BlockContainer <div> at (8,8) content-size 392x34.9375 [BFC] children: inline
           line 0 width: 26.25, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 4, rect: [8,8 26.25x17.46875]
               "left"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div> at (400,8) content-size 392x17.46875 children: inline
+        BlockContainer <div> at (400,8) content-size 392x17.46875 [BFC] children: inline
           line 0 width: 70.234375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 9, rect: [400,8 70.234375x17.46875]
               "right-top"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,8) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,42.9375) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
         TextNode <#text>
-      Box <div.grid-container> at (8,42.9375) content-size 784x17.46875 children: not-inline
-        BlockContainer <(anonymous)> at (8,42.9375) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,42.9375) content-size 784x17.46875 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,42.9375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,42.9375) content-size 261.333343x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,42.9375) content-size 261.333343x17.46875 [BFC] children: inline
           line 0 width: 21.609375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 3, rect: [8,42.9375 21.609375x17.46875]
               "1fr"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,42.9375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,42.9375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,60.40625) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
         TextNode <#text>
-      Box <div.grid-container> at (8,60.40625) content-size 784x17.46875 children: not-inline
-        BlockContainer <(anonymous)> at (8,60.40625) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,60.40625) content-size 784x17.46875 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,60.40625) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,60.40625) content-size 392x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,60.40625) content-size 392x17.46875 [BFC] children: inline
           line 0 width: 21.609375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 3, rect: [8,60.40625 21.609375x17.46875]
               "1fr"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,60.40625) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,60.40625) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,77.875) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
         TextNode <#text>
-      Box <div.grid-container> at (8,77.875) content-size 784x17.46875 children: not-inline
-        BlockContainer <(anonymous)> at (8,77.875) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,77.875) content-size 784x17.46875 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,77.875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,77.875) content-size 196x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,77.875) content-size 196x17.46875 [BFC] children: inline
           line 0 width: 21.609375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 3, rect: [8,77.875 21.609375x17.46875]
               "1fr"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,77.875) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,77.875) content-size 0x0 [BFC] children: inline
           TextNode <#text>
       BlockContainer <(anonymous)> at (8,95.34375) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
         TextNode <#text>
-      Box <div.grid-container> at (8,95.34375) content-size 784x17.46875 children: not-inline
-        BlockContainer <(anonymous)> at (8,95.34375) content-size 0x0 children: inline
+      Box <div.grid-container> at (8,95.34375) content-size 784x17.46875 [GFC] children: not-inline
+        BlockContainer <(anonymous)> at (8,95.34375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
-        BlockContainer <div.grid-item> at (8,95.34375) content-size 196x17.46875 children: inline
+        BlockContainer <div.grid-item> at (8,95.34375) content-size 196x17.46875 [BFC] children: inline
           line 0 width: 21.609375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
             frag 0 from TextNode start: 0, length: 3, rect: [8,95.34375 21.609375x17.46875]
               "1fr"
           TextNode <#text>
-        BlockContainer <(anonymous)> at (8,95.34375) content-size 0x0 children: inline
+        BlockContainer <(anonymous)> at (8,95.34375) content-size 0x0 [BFC] children: inline
           TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/image-display-block-margin-auto.txt b/Tests/LibWeb/Layout/expected/image-display-block-margin-auto.txt
index 354b964149..a443a45ad3 100644
--- a/Tests/LibWeb/Layout/expected/image-display-block-margin-auto.txt
+++ b/Tests/LibWeb/Layout/expected/image-display-block-margin-auto.txt
@@ -1,4 +1,4 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x116 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x116 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 400x100 children: not-inline
       ImageBox <img> at (158,8) content-size 100x100 children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/input-element-with-display-inline.txt b/Tests/LibWeb/Layout/expected/input-element-with-display-inline.txt
index 64f9d6b032..4274ade933 100644
--- a/Tests/LibWeb/Layout/expected/input-element-with-display-inline.txt
+++ b/Tests/LibWeb/Layout/expected/input-element-with-display-inline.txt
@@ -1,9 +1,9 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x45.835937 children: not-inline
+  BlockContainer <html> at (1,1) content-size 798x45.835937 [BFC] children: not-inline
     BlockContainer <body> at (10,10) content-size 780x27.835937 children: inline
       line 0 width: 202, height: 27.835937, bottom: 27.835937, baseline: 25.835937
         frag 0 from BlockContainer start: 0, length: 0, rect: [11,11 200x25.835937]
-      BlockContainer <input> at (11,11) content-size 200x25.835937 inline-block children: not-inline
+      BlockContainer <input> at (11,11) content-size 200x25.835937 inline-block [BFC] children: not-inline
         BlockContainer <#shadow-root> at (11,11) content-size 0x0 children: not-inline
         BlockContainer <div> at (14,13) content-size 194x21.835937 children: inline
           TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/lh-1.txt b/Tests/LibWeb/Layout/expected/lh-1.txt
index d0a936af55..cc65d32ea3 100644
--- a/Tests/LibWeb/Layout/expected/lh-1.txt
+++ b/Tests/LibWeb/Layout/expected/lh-1.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x116 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x116 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x100 children: not-inline
       BlockContainer <div#a> at (8,8) content-size 100x100 children: not-inline
         BlockContainer <div#b> at (8,8) content-size 100x100 children: inline
diff --git a/Tests/LibWeb/Layout/expected/lh-2.txt b/Tests/LibWeb/Layout/expected/lh-2.txt
index d0a936af55..cc65d32ea3 100644
--- a/Tests/LibWeb/Layout/expected/lh-2.txt
+++ b/Tests/LibWeb/Layout/expected/lh-2.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x116 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x116 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x100 children: not-inline
       BlockContainer <div#a> at (8,8) content-size 100x100 children: not-inline
         BlockContainer <div#b> at (8,8) content-size 100x100 children: inline
diff --git a/Tests/LibWeb/Layout/expected/link-sheet.txt b/Tests/LibWeb/Layout/expected/link-sheet.txt
index 0ef7355308..58f8f840f3 100644
--- a/Tests/LibWeb/Layout/expected/link-sheet.txt
+++ b/Tests/LibWeb/Layout/expected/link-sheet.txt
@@ -1,4 +1,4 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x16 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x16 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x0 children: not-inline
-      BlockContainer <div#foo> at (0,0) content-size 123x456 positioned children: not-inline
+      BlockContainer <div#foo> at (0,0) content-size 123x456 positioned [BFC] children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/overflow-x-hidden-with-border-radius.txt b/Tests/LibWeb/Layout/expected/overflow-x-hidden-with-border-radius.txt
index 3924114199..e751117135 100644
--- a/Tests/LibWeb/Layout/expected/overflow-x-hidden-with-border-radius.txt
+++ b/Tests/LibWeb/Layout/expected/overflow-x-hidden-with-border-radius.txt
@@ -1,6 +1,6 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x118 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x118 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x102 children: not-inline
-      BlockContainer <div.box> at (9,9) content-size 100x100 positioned children: not-inline
+      BlockContainer <div.box> at (9,9) content-size 100x100 positioned [BFC] children: not-inline
       BlockContainer <(anonymous)> at (8,110) content-size 784x0 children: inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/position-absolute-from-edges.txt b/Tests/LibWeb/Layout/expected/position-absolute-from-edges.txt
index 36e079d1db..bddcb60187 100644
--- a/Tests/LibWeb/Layout/expected/position-absolute-from-edges.txt
+++ b/Tests/LibWeb/Layout/expected/position-absolute-from-edges.txt
@@ -1,14 +1,14 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x16 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x16 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x0 children: inline
-      BlockContainer <div#container> at (8,8) content-size 500x400 positioned children: inline
+      BlockContainer <div#container> at (8,8) content-size 500x400 positioned [BFC] children: inline
         TextNode <#text>
-        BlockContainer <div#red> at (38,38) content-size 100x100 positioned children: not-inline
+        BlockContainer <div#red> at (38,38) content-size 100x100 positioned [BFC] children: not-inline
         TextNode <#text>
-        BlockContainer <div#green> at (338,78) content-size 100x100 positioned children: not-inline
+        BlockContainer <div#green> at (338,78) content-size 100x100 positioned [BFC] children: not-inline
         TextNode <#text>
-        BlockContainer <div#blue> at (28,288) content-size 100x100 positioned children: not-inline
+        BlockContainer <div#blue> at (28,288) content-size 100x100 positioned [BFC] children: not-inline
         TextNode <#text>
-        BlockContainer <div#yellow> at (388,288) content-size 100x100 positioned children: not-inline
+        BlockContainer <div#yellow> at (388,288) content-size 100x100 positioned [BFC] children: not-inline
         TextNode <#text>
       TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/position-absolute-ignores-padding-of-position-relative-floating-parent.txt b/Tests/LibWeb/Layout/expected/position-absolute-ignores-padding-of-position-relative-floating-parent.txt
index 60130fffa9..13e1b2cb6a 100644
--- a/Tests/LibWeb/Layout/expected/position-absolute-ignores-padding-of-position-relative-floating-parent.txt
+++ b/Tests/LibWeb/Layout/expected/position-absolute-ignores-padding-of-position-relative-floating-parent.txt
@@ -1,6 +1,6 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x216 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x216 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x200 children: not-inline
       BlockContainer <div#guide> at (8,8) content-size 200x200 children: not-inline
-        BlockContainer <div#container> at (18,18) content-size 0x0 positioned floating children: not-inline
-          BlockContainer <div#box> at (8,8) content-size 100x100 positioned children: not-inline
+        BlockContainer <div#container> at (18,18) content-size 0x0 positioned floating [BFC] children: not-inline
+          BlockContainer <div#box> at (8,8) content-size 100x100 positioned [BFC] children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/position-absolute-top-left.txt b/Tests/LibWeb/Layout/expected/position-absolute-top-left.txt
index 7a0d9778d5..c194e91810 100644
--- a/Tests/LibWeb/Layout/expected/position-absolute-top-left.txt
+++ b/Tests/LibWeb/Layout/expected/position-absolute-top-left.txt
@@ -1,20 +1,20 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x616 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x616 [BFC] children: not-inline
     BlockContainer <(anonymous)> at (0,0) content-size 800x0 children: inline
       TextNode <#text>
     BlockContainer <body> at (8,8) content-size 784x600 children: not-inline
       BlockContainer <(anonymous)> at (8,8) content-size 784x0 children: inline
         TextNode <#text>
-        BlockContainer <div.blue.absolute> at (208,208) content-size 200x200 positioned children: inline
+        BlockContainer <div.blue.absolute> at (208,208) content-size 200x200 positioned [BFC] children: inline
           TextNode <#text>
-          BlockContainer <div.red.absolute> at (308,308) content-size 100x100 positioned children: not-inline
+          BlockContainer <div.red.absolute> at (308,308) content-size 100x100 positioned [BFC] children: not-inline
           TextNode <#text>
-          BlockContainer <div.yellow.absolute> at (258,258) content-size 100x100 positioned children: inline
+          BlockContainer <div.yellow.absolute> at (258,258) content-size 100x100 positioned [BFC] children: inline
             TextNode <#text>
-            BlockContainer <div.black.absolute> at (308,308) content-size 50x50 positioned children: not-inline
+            BlockContainer <div.black.absolute> at (308,308) content-size 50x50 positioned [BFC] children: not-inline
             TextNode <#text>
           TextNode <#text>
-          BlockContainer <div.green.absolute> at (508,508) content-size 100x100 positioned children: not-inline
+          BlockContainer <div.green.absolute> at (508,508) content-size 100x100 positioned [BFC] children: not-inline
           TextNode <#text>
         TextNode <#text>
       BlockContainer <div.blue> at (8,8) content-size 200x200 children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/replaced-box-with-vertical-margins.txt b/Tests/LibWeb/Layout/expected/replaced-box-with-vertical-margins.txt
index 40d4e4c77e..dfda66ed8f 100644
--- a/Tests/LibWeb/Layout/expected/replaced-box-with-vertical-margins.txt
+++ b/Tests/LibWeb/Layout/expected/replaced-box-with-vertical-margins.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x232.46875 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x232.46875 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x216.46875 children: inline
       line 0 width: 174.828125, height: 216.46875, bottom: 216.46875, baseline: 213
         frag 0 from TextNode start: 0, length: 6, rect: [8,207 43.125x17.46875]
diff --git a/Tests/LibWeb/Layout/expected/svg-preserve-aspect-ratio.txt b/Tests/LibWeb/Layout/expected/svg-preserve-aspect-ratio.txt
index 9edb924aa1..451f6770d7 100644
--- a/Tests/LibWeb/Layout/expected/svg-preserve-aspect-ratio.txt
+++ b/Tests/LibWeb/Layout/expected/svg-preserve-aspect-ratio.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x273.46875 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x273.46875 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x257.46875 children: inline
       line 0 width: 772, height: 130.46875, bottom: 130.46875, baseline: 127
         frag 0 from SVGSVGBox start: 0, length: 0, rect: [9,84 100x50]
@@ -38,67 +38,67 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
         frag 7 from TextNode start: 0, length: 1, rect: [240,248 8x17.46875]
           " "
         frag 8 from SVGSVGBox start: 0, length: 0, rect: [249,201 160x60]
-      SVGSVGBox <svg> at (9,84) content-size 100x50 children: inline
+      SVGSVGBox <svg> at (9,84) content-size 100x50 [SVG] children: inline
         TextNode <#text>
         SVGGeometryBox <circle> at (34,84) content-size 50x50 children: not-inline
         TextNode <#text>
       TextNode <#text>
-      SVGSVGBox <svg> at (119,84) content-size 100x50 children: inline
+      SVGSVGBox <svg> at (119,84) content-size 100x50 [SVG] children: inline
         TextNode <#text>
         SVGGeometryBox <circle> at (119,84) content-size 50x50 children: not-inline
         TextNode <#text>
       TextNode <#text>
-      SVGSVGBox <svg> at (229,84) content-size 100x50 children: inline
+      SVGSVGBox <svg> at (229,84) content-size 100x50 [SVG] children: inline
         TextNode <#text>
         SVGGeometryBox <circle> at (279,84) content-size 50x50 children: not-inline
         TextNode <#text>
       TextNode <#text>
-      SVGSVGBox <svg> at (339,84) content-size 100x50 children: inline
+      SVGSVGBox <svg> at (339,84) content-size 100x50 [SVG] children: inline
         TextNode <#text>
         SVGGeometryBox <circle> at (339,84) content-size 100x100 children: not-inline
         TextNode <#text>
       TextNode <#text>
-      SVGSVGBox <svg> at (449,84) content-size 100x50 children: inline
+      SVGSVGBox <svg> at (449,84) content-size 100x50 [SVG] children: inline
         TextNode <#text>
         SVGGeometryBox <circle> at (449,59) content-size 100x100 children: not-inline
         TextNode <#text>
       TextNode <#text>
-      SVGSVGBox <svg> at (559,84) content-size 100x50 children: inline
+      SVGSVGBox <svg> at (559,84) content-size 100x50 [SVG] children: inline
         TextNode <#text>
         SVGGeometryBox <circle> at (559,34) content-size 100x100 children: not-inline
         TextNode <#text>
       TextNode <#text>
-      SVGSVGBox <svg> at (669,9) content-size 50x125 children: inline
+      SVGSVGBox <svg> at (669,9) content-size 50x125 [SVG] children: inline
         TextNode <#text>
         SVGGeometryBox <circle> at (669,9) content-size 50x50 children: not-inline
         TextNode <#text>
       TextNode <#text>
-      SVGSVGBox <svg> at (729,9) content-size 50x125 children: inline
+      SVGSVGBox <svg> at (729,9) content-size 50x125 [SVG] children: inline
         TextNode <#text>
         SVGGeometryBox <circle> at (729,46.5) content-size 50x50 children: not-inline
         TextNode <#text>
       TextNode <#text>
-      SVGSVGBox <svg> at (9,136) content-size 50x125 children: inline
+      SVGSVGBox <svg> at (9,136) content-size 50x125 [SVG] children: inline
         TextNode <#text>
         SVGGeometryBox <circle> at (9,211) content-size 50x50 children: not-inline
         TextNode <#text>
       TextNode <#text>
-      SVGSVGBox <svg> at (69,136) content-size 50x125 children: inline
+      SVGSVGBox <svg> at (69,136) content-size 50x125 [SVG] children: inline
         TextNode <#text>
         SVGGeometryBox <circle> at (69,136) content-size 125x125 children: not-inline
         TextNode <#text>
       TextNode <#text>
-      SVGSVGBox <svg> at (129,136) content-size 50x125 children: inline
+      SVGSVGBox <svg> at (129,136) content-size 50x125 [SVG] children: inline
         TextNode <#text>
         SVGGeometryBox <circle> at (91.5,136) content-size 125x125 children: not-inline
         TextNode <#text>
       TextNode <#text>
-      SVGSVGBox <svg> at (189,136) content-size 50x125 children: inline
+      SVGSVGBox <svg> at (189,136) content-size 50x125 [SVG] children: inline
         TextNode <#text>
         SVGGeometryBox <circle> at (114,136) content-size 125x125 children: not-inline
         TextNode <#text>
       TextNode <#text>
-      SVGSVGBox <svg> at (249,201) content-size 160x60 children: inline
+      SVGSVGBox <svg> at (249,201) content-size 160x60 [SVG] children: inline
         TextNode <#text>
         SVGGeometryBox <circle> at (299,201) content-size 60x60 children: not-inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/svg-transforms-and-viewboxes.txt b/Tests/LibWeb/Layout/expected/svg-transforms-and-viewboxes.txt
index 714224f861..3a0ff36f89 100644
--- a/Tests/LibWeb/Layout/expected/svg-transforms-and-viewboxes.txt
+++ b/Tests/LibWeb/Layout/expected/svg-transforms-and-viewboxes.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x700 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x700 [BFC] children: not-inline
     BlockContainer <body> at (50,50) content-size 700x600 children: inline
       line 0 width: 616, height: 203.46875, bottom: 203.46875, baseline: 200
         frag 0 from SVGSVGBox start: 0, length: 0, rect: [50,150 200x100]
@@ -19,7 +19,7 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
         frag 4 from SVGSVGBox start: 0, length: 0, rect: [466,250 200x200]
       line 2 width: 200, height: 200, bottom: 600, baseline: 200
         frag 0 from SVGSVGBox start: 0, length: 0, rect: [50,450 200x200]
-      SVGSVGBox <svg> at (50,150) content-size 200x100 children: inline
+      SVGSVGBox <svg> at (50,150) content-size 200x100 [SVG] children: inline
         TextNode <#text>
         SVGGraphicsBox <g>  children: inline
           TextNode <#text>
@@ -32,21 +32,21 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
           TextNode <#text>
         TextNode <#text>
       TextNode <#text>
-      SVGSVGBox <svg> at (258,50) content-size 200x200 children: inline
+      SVGSVGBox <svg> at (258,50) content-size 200x200 [SVG] children: inline
         TextNode <#text>
         SVGGeometryBox <rect> at (268,60) content-size 30x20 children: not-inline
         TextNode <#text>
         SVGGeometryBox <rect> at (288,130) content-size 110x90 children: not-inline
         TextNode <#text>
       TextNode <#text>
-      SVGSVGBox <svg> at (466,50) content-size 200x200 children: inline
+      SVGSVGBox <svg> at (466,50) content-size 200x200 [SVG] children: inline
         TextNode <#text>
         SVGGeometryBox <rect> at (506,90) content-size 120x120 children: not-inline
         TextNode <#text>
         SVGGeometryBox <rect> at (471.358978,90) content-size 189.282043x120 children: not-inline
         TextNode <#text>
       TextNode <#text>
-      SVGSVGBox <svg> at (50,250) content-size 200x200 children: inline
+      SVGSVGBox <svg> at (50,250) content-size 200x200 [SVG] children: inline
         TextNode <#text>
         SVGGeometryBox <rect> at (120.588233,320.588256) content-size 58.823524x58.823532 children: not-inline
         TextNode <#text>
@@ -57,7 +57,7 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
         SVGGeometryBox <rect> at (179.411773,321.481903) content-size 68.14447x68.14447 children: not-inline
         TextNode <#text>
       TextNode <#text>
-      SVGSVGBox <svg> at (258,250) content-size 200x200 children: inline
+      SVGSVGBox <svg> at (258,250) content-size 200x200 [SVG] children: inline
         TextNode <#text>
         TextNode <#text>
         SVGGeometryBox <circle> at (278,270) content-size 160x160 children: not-inline
@@ -72,14 +72,14 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
         SVGGeometryBox <circle> at (338,330) content-size 40x40 children: not-inline
         TextNode <#text>
       TextNode <#text>
-      SVGSVGBox <svg> at (466,250) content-size 200x200 children: inline
+      SVGSVGBox <svg> at (466,250) content-size 200x200 [SVG] children: inline
         TextNode <#text>
         SVGGeometryBox <rect> at (506,290) content-size 120x120 children: not-inline
         TextNode <#text>
         SVGGeometryBox <rect> at (506,255.358978) content-size 120x189.282043 children: not-inline
         TextNode <#text>
       TextNode <#text>
-      SVGSVGBox <svg> at (50,450) content-size 200x200 children: inline
+      SVGSVGBox <svg> at (50,450) content-size 200x200 [SVG] children: inline
         TextNode <#text>
         TextNode <#text>
         SVGGeometryBox <rect> at (60,460) content-size 80x80 children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/svg/svg-inside-svg.txt b/Tests/LibWeb/Layout/expected/svg/svg-inside-svg.txt
index b8b8734e33..6a58f729d8 100644
--- a/Tests/LibWeb/Layout/expected/svg/svg-inside-svg.txt
+++ b/Tests/LibWeb/Layout/expected/svg/svg-inside-svg.txt
@@ -1,10 +1,10 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x40 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x40 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x24 children: inline
       line 0 width: 24, height: 24, bottom: 24, baseline: 24
         frag 0 from SVGSVGBox start: 0, length: 0, rect: [8,8 24x24]
-      SVGSVGBox <svg> at (8,8) content-size 24x24 children: inline
+      SVGSVGBox <svg> at (8,8) content-size 24x24 [SVG] children: inline
         SVGGraphicsBox <g>  children: inline
-          SVGSVGBox <svg> at (8,8) content-size 24x24 children: not-inline
+          SVGSVGBox <svg> at (8,8) content-size 24x24 [SVG] children: not-inline
             SVGGeometryBox <rect> at (8,8) content-size 24x24 children: not-inline
         TextNode <#text>
diff --git a/Tests/LibWeb/Layout/expected/svg/svg-path-with-implicit-lineto.txt b/Tests/LibWeb/Layout/expected/svg/svg-path-with-implicit-lineto.txt
index 0ab32ff1f7..e4b1320c1b 100644
--- a/Tests/LibWeb/Layout/expected/svg/svg-path-with-implicit-lineto.txt
+++ b/Tests/LibWeb/Layout/expected/svg/svg-path-with-implicit-lineto.txt
@@ -1,7 +1,7 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x116 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x116 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x100 children: inline
       line 0 width: 100, height: 100, bottom: 100, baseline: 60
         frag 0 from SVGSVGBox start: 0, length: 0, rect: [8,8 100x100]
-      SVGSVGBox <svg> at (8,8) content-size 100x100 children: not-inline
+      SVGSVGBox <svg> at (8,8) content-size 100x100 [SVG] children: not-inline
         SVGGeometryBox <path> at (28,28) content-size 60x60 children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/table/auto-height.txt b/Tests/LibWeb/Layout/expected/table/auto-height.txt
index ffaddfe2f6..3d018b8b84 100644
--- a/Tests/LibWeb/Layout/expected/table/auto-height.txt
+++ b/Tests/LibWeb/Layout/expected/table/auto-height.txt
@@ -1,20 +1,20 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x60.9375 children: not-inline
+  BlockContainer <html> at (1,1) content-size 798x60.9375 [BFC] children: not-inline
     BlockContainer <body> at (10,10) content-size 780x42.9375 children: not-inline
       BlockContainer <div> at (11,11) content-size 778x19.46875 children: not-inline
-        TableWrapper <(anonymous)> at (11,11) content-size 29.15625x19.46875 children: not-inline
-          TableBox <(anonymous)> at (11,11) content-size 29.15625x19.46875 children: not-inline
+        TableWrapper <(anonymous)> at (11,11) content-size 29.15625x19.46875 [BFC] children: not-inline
+          TableBox <(anonymous)> at (11,11) content-size 29.15625x19.46875 [TFC] children: not-inline
             TableRowBox <(anonymous)> at (11,11) content-size 29.15625x19.46875 children: not-inline
-              TableCellBox <span> at (12,12) content-size 27.15625x17.46875 children: inline
+              TableCellBox <span> at (12,12) content-size 27.15625x17.46875 [BFC] children: inline
                 line 0 width: 27.15625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                   frag 0 from TextNode start: 0, length: 3, rect: [12,12 27.15625x17.46875]
                     "foo"
                 TextNode <#text>
       BlockContainer <div> at (11,32.46875) content-size 778x19.46875 children: not-inline
-        TableWrapper <(anonymous)> at (11,32.46875) content-size 29.640625x19.46875 children: not-inline
-          TableBox <(anonymous)> at (11,32.46875) content-size 29.640625x19.46875 children: not-inline
+        TableWrapper <(anonymous)> at (11,32.46875) content-size 29.640625x19.46875 [BFC] children: not-inline
+          TableBox <(anonymous)> at (11,32.46875) content-size 29.640625x19.46875 [TFC] children: not-inline
             TableRowBox <(anonymous)> at (11,32.46875) content-size 29.640625x19.46875 children: not-inline
-              TableCellBox <span> at (12,33.46875) content-size 27.640625x17.46875 children: inline
+              TableCellBox <span> at (12,33.46875) content-size 27.640625x17.46875 [BFC] children: inline
                 line 0 width: 27.640625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                   frag 0 from TextNode start: 0, length: 3, rect: [12,33.46875 27.640625x17.46875]
                     "bar"
diff --git a/Tests/LibWeb/Layout/expected/table/basic.txt b/Tests/LibWeb/Layout/expected/table/basic.txt
index 71959087d6..0e60cebb52 100644
--- a/Tests/LibWeb/Layout/expected/table/basic.txt
+++ b/Tests/LibWeb/Layout/expected/table/basic.txt
@@ -1,16 +1,16 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x74.40625 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x74.40625 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x58.40625 children: not-inline
-      TableWrapper <(anonymous)> at (8,8) content-size 784x0 children: not-inline
-        TableBox <table#empty-table> at (8,8) content-size 784x0 children: not-inline
+      TableWrapper <(anonymous)> at (8,8) content-size 784x0 [BFC] children: not-inline
+        TableBox <table#empty-table> at (8,8) content-size 784x0 [TFC] children: not-inline
       BlockContainer <(anonymous)> at (8,8) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
-      TableWrapper <(anonymous)> at (8,8) content-size 95.171875x58.40625 children: not-inline
-        TableBox <table#full-table> at (8,8) content-size 95.171875x58.40625 children: not-inline
+      TableWrapper <(anonymous)> at (8,8) content-size 95.171875x58.40625 [BFC] children: not-inline
+        TableBox <table#full-table> at (8,8) content-size 95.171875x58.40625 [TFC] children: not-inline
           BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
             TextNode <#text>
-          BlockContainer <caption> at (8,8) content-size 0x0 children: inline
+          BlockContainer <caption> at (8,8) content-size 0x0 [BFC] children: inline
             TextNode <#text>
           BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
             TextNode <#text>
@@ -20,7 +20,7 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
             TableRowBox <tr> at (8,8) content-size 95.171875x19.46875 children: not-inline
               BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
                 TextNode <#text>
-              TableCellBox <td> at (9,9) content-size 93.171875x17.46875 children: inline
+              TableCellBox <td> at (9,9) content-size 93.171875x17.46875 [BFC] children: inline
                 line 0 width: 73.65625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                   frag 0 from TextNode start: 0, length: 9, rect: [9,9 73.65625x17.46875]
                     "Head Cell"
@@ -37,7 +37,7 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
             TableRowBox <tr> at (8,27.46875) content-size 95.171875x19.46875 children: not-inline
               BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
                 TextNode <#text>
-              TableCellBox <td> at (9,28.46875) content-size 93.171875x17.46875 children: inline
+              TableCellBox <td> at (9,28.46875) content-size 93.171875x17.46875 [BFC] children: inline
                 line 0 width: 70.234375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                   frag 0 from TextNode start: 0, length: 9, rect: [9,28.46875 70.234375x17.46875]
                     "Body Cell"
@@ -54,7 +54,7 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
             TableRowBox <tr> at (8,46.9375) content-size 95.171875x19.46875 children: not-inline
               BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
                 TextNode <#text>
-              TableCellBox <td> at (9,47.9375) content-size 93.171875x17.46875 children: inline
+              TableCellBox <td> at (9,47.9375) content-size 93.171875x17.46875 [BFC] children: inline
                 line 0 width: 93.171875, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                   frag 0 from TextNode start: 0, length: 11, rect: [9,47.9375 93.171875x17.46875]
                     "Footer Cell"
diff --git a/Tests/LibWeb/Layout/expected/table/borders.txt b/Tests/LibWeb/Layout/expected/table/borders.txt
index 1472cbd8cf..94e0fe83f9 100644
--- a/Tests/LibWeb/Layout/expected/table/borders.txt
+++ b/Tests/LibWeb/Layout/expected/table/borders.txt
@@ -1,22 +1,22 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x293.625 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x293.625 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x277.625 children: not-inline
-      TableWrapper <(anonymous)> at (8,8) content-size 164.296875x66.40625 children: not-inline
-        TableBox <table.table-border-black> at (9,9) content-size 164.296875x64.40625 children: not-inline
+      TableWrapper <(anonymous)> at (8,8) content-size 164.296875x66.40625 [BFC] children: not-inline
+        TableBox <table.table-border-black> at (9,9) content-size 164.296875x64.40625 [TFC] children: not-inline
           BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
             TextNode <#text>
           TableRowGroupBox <tbody> at (9,9) content-size 166.296875x64.40625 children: not-inline
             TableRowBox <tr> at (9,9) content-size 166.296875x21.46875 children: not-inline
               BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
                 TextNode <#text>
-              TableCellBox <td> at (11,11) content-size 82.015625x17.46875 children: inline
+              TableCellBox <td> at (11,11) content-size 82.015625x17.46875 [BFC] children: inline
                 line 0 width: 82.015625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                   frag 0 from TextNode start: 0, length: 9, rect: [11,11 82.015625x17.46875]
                     "Firstname"
                 TextNode <#text>
               BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
                 TextNode <#text>
-              TableCellBox <td> at (97.015625,11) content-size 76.28125x17.46875 children: inline
+              TableCellBox <td> at (97.015625,11) content-size 76.28125x17.46875 [BFC] children: inline
                 line 0 width: 76.28125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                   frag 0 from TextNode start: 0, length: 8, rect: [97.015625,11 76.28125x17.46875]
                     "Lastname"
@@ -28,14 +28,14 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
             TableRowBox <tr> at (9,30.46875) content-size 166.296875x21.46875 children: not-inline
               BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
                 TextNode <#text>
-              TableCellBox <td> at (11,32.46875) content-size 82.015625x17.46875 children: inline
+              TableCellBox <td> at (11,32.46875) content-size 82.015625x17.46875 [BFC] children: inline
                 line 0 width: 44.65625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                   frag 0 from TextNode start: 0, length: 5, rect: [11,32.46875 44.65625x17.46875]
                     "Peter"
                 TextNode <#text>
               BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
                 TextNode <#text>
-              TableCellBox <td> at (97.015625,32.46875) content-size 76.28125x17.46875 children: inline
+              TableCellBox <td> at (97.015625,32.46875) content-size 76.28125x17.46875 [BFC] children: inline
                 line 0 width: 53.671875, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                   frag 0 from TextNode start: 0, length: 7, rect: [97.015625,32.46875 53.671875x17.46875]
                     "Griffin"
@@ -47,14 +47,14 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
             TableRowBox <tr> at (9,51.9375) content-size 166.296875x21.46875 children: not-inline
               BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
                 TextNode <#text>
-              TableCellBox <td> at (11,53.9375) content-size 82.015625x17.46875 children: inline
+              TableCellBox <td> at (11,53.9375) content-size 82.015625x17.46875 [BFC] children: inline
                 line 0 width: 35.125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                   frag 0 from TextNode start: 0, length: 4, rect: [11,53.9375 35.125x17.46875]
                     "Lois"
                 TextNode <#text>
               BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
                 TextNode <#text>
-              TableCellBox <td> at (97.015625,53.9375) content-size 76.28125x17.46875 children: inline
+              TableCellBox <td> at (97.015625,53.9375) content-size 76.28125x17.46875 [BFC] children: inline
                 line 0 width: 53.671875, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                   frag 0 from TextNode start: 0, length: 7, rect: [97.015625,53.9375 53.671875x17.46875]
                     "Griffin"
@@ -66,22 +66,22 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
       BlockContainer <(anonymous)> at (8,74.40625) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
-      TableWrapper <(anonymous)> at (8,74.40625) content-size 164.296875x62.40625 children: not-inline
-        TableBox <table.table-border-black> at (8,74.40625) content-size 164.296875x62.40625 children: not-inline
+      TableWrapper <(anonymous)> at (8,74.40625) content-size 164.296875x62.40625 [BFC] children: not-inline
+        TableBox <table.table-border-black> at (8,74.40625) content-size 164.296875x62.40625 [TFC] children: not-inline
           BlockContainer <(anonymous)> at (8,74.40625) content-size 0x0 children: inline
             TextNode <#text>
           TableRowGroupBox <tbody> at (8,74.40625) content-size 164.296875x62.40625 children: not-inline
             TableRowBox <tr> at (8,74.40625) content-size 164.296875x20.46875 children: not-inline
               BlockContainer <(anonymous)> at (8,74.40625) content-size 0x0 children: inline
                 TextNode <#text>
-              TableCellBox <td> at (9,75.40625) content-size 82.015625x17.46875 children: inline
+              TableCellBox <td> at (9,75.40625) content-size 82.015625x17.46875 [BFC] children: inline
                 line 0 width: 82.015625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                   frag 0 from TextNode start: 0, length: 9, rect: [9,75.40625 82.015625x17.46875]
                     "Firstname"
                 TextNode <#text>
               BlockContainer <(anonymous)> at (8,74.40625) content-size 0x0 children: inline
                 TextNode <#text>
-              TableCellBox <td> at (95.015625,75.40625) content-size 76.28125x17.46875 children: inline
+              TableCellBox <td> at (95.015625,75.40625) content-size 76.28125x17.46875 [BFC] children: inline
                 line 0 width: 76.28125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                   frag 0 from TextNode start: 0, length: 8, rect: [95.015625,75.40625 76.28125x17.46875]
                     "Lastname"
@@ -93,14 +93,14 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
             TableRowBox <tr> at (8,94.875) content-size 164.296875x21.46875 children: not-inline
               BlockContainer <(anonymous)> at (8,74.40625) content-size 0x0 children: inline
                 TextNode <#text>
-              TableCellBox <td> at (9,96.875) content-size 82.015625x17.46875 children: inline
+              TableCellBox <td> at (9,96.875) content-size 82.015625x17.46875 [BFC] children: inline
                 line 0 width: 44.65625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                   frag 0 from TextNode start: 0, length: 5, rect: [9,96.875 44.65625x17.46875]
                     "Peter"
                 TextNode <#text>
               BlockContainer <(anonymous)> at (8,74.40625) content-size 0x0 children: inline
                 TextNode <#text>
-              TableCellBox <td> at (95.015625,96.875) content-size 76.28125x17.46875 children: inline
+              TableCellBox <td> at (95.015625,96.875) content-size 76.28125x17.46875 [BFC] children: inline
                 line 0 width: 53.671875, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                   frag 0 from TextNode start: 0, length: 7, rect: [95.015625,96.875 53.671875x17.46875]
                     "Griffin"
@@ -112,14 +112,14 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
             TableRowBox <tr> at (8,116.34375) content-size 164.296875x20.46875 children: not-inline
               BlockContainer <(anonymous)> at (8,74.40625) content-size 0x0 children: inline
                 TextNode <#text>
-              TableCellBox <td> at (9,118.34375) content-size 82.015625x17.46875 children: inline
+              TableCellBox <td> at (9,118.34375) content-size 82.015625x17.46875 [BFC] children: inline
                 line 0 width: 35.125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                   frag 0 from TextNode start: 0, length: 4, rect: [9,118.34375 35.125x17.46875]
                     "Lois"
                 TextNode <#text>
               BlockContainer <(anonymous)> at (8,74.40625) content-size 0x0 children: inline
                 TextNode <#text>
-              TableCellBox <td> at (95.015625,118.34375) content-size 76.28125x17.46875 children: inline
+              TableCellBox <td> at (95.015625,118.34375) content-size 76.28125x17.46875 [BFC] children: inline
                 line 0 width: 53.671875, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                   frag 0 from TextNode start: 0, length: 7, rect: [95.015625,118.34375 53.671875x17.46875]
                     "Griffin"
@@ -131,21 +131,21 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
       BlockContainer <(anonymous)> at (8,136.8125) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
-      TableWrapper <(anonymous)> at (8,136.8125) content-size 160.296875x56.40625 children: not-inline
-        TableBox <div.table.border-black> at (8,136.8125) content-size 160.296875x56.40625 children: not-inline
+      TableWrapper <(anonymous)> at (8,136.8125) content-size 160.296875x56.40625 [BFC] children: not-inline
+        TableBox <div.table.border-black> at (8,136.8125) content-size 160.296875x56.40625 [TFC] children: not-inline
           BlockContainer <(anonymous)> at (8,136.8125) content-size 0x0 children: inline
             TextNode <#text>
           TableRowBox <div.table-row.border-black> at (8,136.8125) content-size 160.296875x18.46875 children: not-inline
             BlockContainer <(anonymous)> at (8,136.8125) content-size 0x0 children: inline
               TextNode <#text>
-            TableCellBox <div.table-cell.border-black> at (8,136.8125) content-size 82.015625x17.46875 children: inline
+            TableCellBox <div.table-cell.border-black> at (8,136.8125) content-size 82.015625x17.46875 [BFC] children: inline
               line 0 width: 82.015625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                 frag 0 from TextNode start: 0, length: 9, rect: [8,136.8125 82.015625x17.46875]
                   "Firstname"
               TextNode <#text>
             BlockContainer <(anonymous)> at (8,136.8125) content-size 0x0 children: inline
               TextNode <#text>
-            TableCellBox <div.table-cell.border-black> at (92.015625,136.8125) content-size 76.28125x17.46875 children: inline
+            TableCellBox <div.table-cell.border-black> at (92.015625,136.8125) content-size 76.28125x17.46875 [BFC] children: inline
               line 0 width: 76.28125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                 frag 0 from TextNode start: 0, length: 8, rect: [92.015625,136.8125 76.28125x17.46875]
                   "Lastname"
@@ -157,14 +157,14 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
           TableRowBox <div.table-row.border-black> at (8,155.28125) content-size 160.296875x19.46875 children: not-inline
             BlockContainer <(anonymous)> at (8,136.8125) content-size 0x0 children: inline
               TextNode <#text>
-            TableCellBox <div.table-cell.border-black> at (8,156.28125) content-size 82.015625x17.46875 children: inline
+            TableCellBox <div.table-cell.border-black> at (8,156.28125) content-size 82.015625x17.46875 [BFC] children: inline
               line 0 width: 44.65625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                 frag 0 from TextNode start: 0, length: 5, rect: [8,156.28125 44.65625x17.46875]
                   "Peter"
               TextNode <#text>
             BlockContainer <(anonymous)> at (8,136.8125) content-size 0x0 children: inline
               TextNode <#text>
-            TableCellBox <div.table-cell.border-black> at (92.015625,156.28125) content-size 76.28125x17.46875 children: inline
+            TableCellBox <div.table-cell.border-black> at (92.015625,156.28125) content-size 76.28125x17.46875 [BFC] children: inline
               line 0 width: 53.671875, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                 frag 0 from TextNode start: 0, length: 7, rect: [92.015625,156.28125 53.671875x17.46875]
                   "Griffin"
@@ -176,14 +176,14 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
           TableRowBox <div.table-row.border-black> at (8,174.75) content-size 160.296875x18.46875 children: not-inline
             BlockContainer <(anonymous)> at (8,136.8125) content-size 0x0 children: inline
               TextNode <#text>
-            TableCellBox <div.table-cell.border-black> at (8,175.75) content-size 82.015625x17.46875 children: inline
+            TableCellBox <div.table-cell.border-black> at (8,175.75) content-size 82.015625x17.46875 [BFC] children: inline
               line 0 width: 35.125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                 frag 0 from TextNode start: 0, length: 4, rect: [8,175.75 35.125x17.46875]
                   "Lois"
               TextNode <#text>
             BlockContainer <(anonymous)> at (8,136.8125) content-size 0x0 children: inline
               TextNode <#text>
-            TableCellBox <div.table-cell.border-black> at (92.015625,175.75) content-size 76.28125x17.46875 children: inline
+            TableCellBox <div.table-cell.border-black> at (92.015625,175.75) content-size 76.28125x17.46875 [BFC] children: inline
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                 frag 0 from TextNode start: 0, length: 7, rect: [92.015625,175.75 53.671875x17.46875]
                   "Griffin"
@@ -195,21 +195,21 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
       BlockContainer <(anonymous)> at (8,193.21875) content-size 784x0 children: inline
         TextNode <#text>
         TextNode <#text>
-      TableWrapper <(anonymous)> at (8,193.21875) content-size 178.296875x92.40625 children: not-inline
-        TableBox <div.table.thick-border-black> at (8,193.21875) content-size 178.296875x92.40625 children: not-inline
+      TableWrapper <(anonymous)> at (8,193.21875) content-size 178.296875x92.40625 [BFC] children: not-inline
+        TableBox <div.table.thick-border-black> at (8,193.21875) content-size 178.296875x92.40625 [TFC] children: not-inline
           BlockContainer <(anonymous)> at (8,193.21875) content-size 0x0 children: inline
             TextNode <#text>
           TableRowBox <div.table-row.thick-border-black> at (8,193.21875) content-size 178.296875x27.46875 children: not-inline
             BlockContainer <(anonymous)> at (8,193.21875) content-size 0x0 children: inline
               TextNode <#text>
-            TableCellBox <div.table-cell.thick-border-black> at (8,193.21875) content-size 82.015625x17.46875 children: inline
+            TableCellBox <div.table-cell.thick-border-black> at (8,193.21875) content-size 82.015625x17.46875 [BFC] children: inline
               line 0 width: 82.015625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                 frag 0 from TextNode start: 0, length: 9, rect: [8,193.21875 82.015625x17.46875]
                   "Firstname"
               TextNode <#text>
             BlockContainer <(anonymous)> at (8,193.21875) content-size 0x0 children: inline
               TextNode <#text>
-            TableCellBox <div.table-cell.thick-border-black> at (110.015625,193.21875) content-size 76.28125x17.46875 children: inline
+            TableCellBox <div.table-cell.thick-border-black> at (110.015625,193.21875) content-size 76.28125x17.46875 [BFC] children: inline
               line 0 width: 76.28125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                 frag 0 from TextNode start: 0, length: 8, rect: [110.015625,193.21875 76.28125x17.46875]
                   "Lastname"
@@ -221,14 +221,14 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
           TableRowBox <div.table-row.thick-border-black> at (8,220.6875) content-size 178.296875x37.46875 children: not-inline
             BlockContainer <(anonymous)> at (8,193.21875) content-size 0x0 children: inline
               TextNode <#text>
-            TableCellBox <div.table-cell.thick-border-black> at (8,230.6875) content-size 82.015625x17.46875 children: inline
+            TableCellBox <div.table-cell.thick-border-black> at (8,230.6875) content-size 82.015625x17.46875 [BFC] children: inline
               line 0 width: 44.65625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                 frag 0 from TextNode start: 0, length: 5, rect: [8,230.6875 44.65625x17.46875]
                   "Peter"
               TextNode <#text>
             BlockContainer <(anonymous)> at (8,193.21875) content-size 0x0 children: inline
               TextNode <#text>
-            TableCellBox <div.table-cell.thick-border-black> at (110.015625,230.6875) content-size 76.28125x17.46875 children: inline
+            TableCellBox <div.table-cell.thick-border-black> at (110.015625,230.6875) content-size 76.28125x17.46875 [BFC] children: inline
               line 0 width: 53.671875, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                 frag 0 from TextNode start: 0, length: 7, rect: [110.015625,230.6875 53.671875x17.46875]
                   "Griffin"
@@ -240,14 +240,14 @@ Viewport <#document> at (0,0) content-size 800x600 children: not-inline
           TableRowBox <div.table-row.thick-border-black> at (8,258.15625) content-size 178.296875x27.46875 children: not-inline
             BlockContainer <(anonymous)> at (8,193.21875) content-size 0x0 children: inline
               TextNode <#text>
-            TableCellBox <div.table-cell.thick-border-black> at (8,268.15625) content-size 82.015625x17.46875 children: inline
+            TableCellBox <div.table-cell.thick-border-black> at (8,268.15625) content-size 82.015625x17.46875 [BFC] children: inline
               line 0 width: 35.125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                 frag 0 from TextNode start: 0, length: 4, rect: [8,268.15625 35.125x17.46875]
                   "Lois"
               TextNode <#text>
             BlockContainer <(anonymous)> at (8,193.21875) content-size 0x0 children: inline
               TextNode <#text>
-            TableCellBox <div.table-cell.thick-border-black> at (110.015625,268.15625) content-size 76.28125x17.46875 children: inline
+            TableCellBox <div.table-cell.thick-border-black> at (110.015625,268.15625) content-size 76.28125x17.46875 [BFC] children: inline
               line 0 width: 53.671875, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                 frag 0 from TextNode start: 0, length: 7, rect: [110.015625,268.15625 53.671875x17.46875]
                   "Griffin"
diff --git a/Tests/LibWeb/Layout/expected/table/cell-px-height.txt b/Tests/LibWeb/Layout/expected/table/cell-px-height.txt
index fa68c787f0..f300f37411 100644
--- a/Tests/LibWeb/Layout/expected/table/cell-px-height.txt
+++ b/Tests/LibWeb/Layout/expected/table/cell-px-height.txt
@@ -1,6 +1,6 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x116 children: not-inline
-    TableWrapper <(anonymous)> at (8,8) content-size 102x100 children: not-inline
-      TableBox <body> at (8,8) content-size 102x100 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x116 [BFC] children: not-inline
+    TableWrapper <(anonymous)> at (8,8) content-size 102x100 [BFC] children: not-inline
+      TableBox <body> at (8,8) content-size 102x100 [TFC] children: not-inline
         TableRowBox <div.row> at (8,8) content-size 102x100 children: not-inline
-          TableCellBox <div.cell> at (9,9) content-size 100x0 children: not-inline
+          TableCellBox <div.cell> at (9,9) content-size 100x0 [BFC] children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/table/columns-width-distribution-1.txt b/Tests/LibWeb/Layout/expected/table/columns-width-distribution-1.txt
index 8d2cdcefe0..694f421df8 100644
--- a/Tests/LibWeb/Layout/expected/table/columns-width-distribution-1.txt
+++ b/Tests/LibWeb/Layout/expected/table/columns-width-distribution-1.txt
@@ -1,15 +1,15 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x108.21875 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x108.21875 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x92.21875 children: not-inline
-      TableWrapper <(anonymous)> at (8,8) content-size 782x92.21875 children: not-inline
-        TableBox <table.ambox> at (9,9) content-size 782x90.21875 children: not-inline
+      TableWrapper <(anonymous)> at (8,8) content-size 782x92.21875 [BFC] children: not-inline
+        TableBox <table.ambox> at (9,9) content-size 782x90.21875 [TFC] children: not-inline
           BlockContainer <(anonymous)> at (8,8) content-size 0x0 children: inline
             TextNode <#text>
           TableRowGroupBox <tbody> at (9,9) content-size 782x90.21875 children: not-inline
             TableRowBox <tr> at (9,9) content-size 782x90.21875 children: not-inline
-              TableCellBox <td.mbox-image> at (10,29.109375) content-size 50x50 children: not-inline
+              TableCellBox <td.mbox-image> at (10,29.109375) content-size 50x50 [BFC] children: not-inline
                 BlockContainer <div.mbox-image-div> at (10,29.109375) content-size 50x50 children: not-inline
-              TableCellBox <td.mbox-text> at (62,10) content-size 728x88.21875 children: inline
+              TableCellBox <td.mbox-text> at (62,10) content-size 728x88.21875 [BFC] children: inline
                 line 0 width: 689.640625, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                   frag 0 from TextNode start: 1, length: 84, rect: [62,10 689.640625x17.46875]
                     "In a scene set in a lawyer's office, the lawyer sits alone and bounces a rubber ball"
diff --git a/Tests/LibWeb/Layout/expected/table/in-auto-height-flex-item.txt b/Tests/LibWeb/Layout/expected/table/in-auto-height-flex-item.txt
index 60623d70d7..93f4bd5f14 100644
--- a/Tests/LibWeb/Layout/expected/table/in-auto-height-flex-item.txt
+++ b/Tests/LibWeb/Layout/expected/table/in-auto-height-flex-item.txt
@@ -1,11 +1,11 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x39.46875 children: not-inline
-    Box <body> at (10,10) content-size 764x21.46875 flex-container(row) children: not-inline
-      BlockContainer <div.upper> at (11,11) content-size 41.78125x19.46875 flex-item children: not-inline
-        TableWrapper <(anonymous)> at (11,11) content-size 41.78125x19.46875 children: not-inline
-          TableBox <(anonymous)> at (11,11) content-size 41.78125x19.46875 children: not-inline
+  BlockContainer <html> at (1,1) content-size 798x39.46875 [BFC] children: not-inline
+    Box <body> at (10,10) content-size 764x21.46875 flex-container(row) [FFC] children: not-inline
+      BlockContainer <div.upper> at (11,11) content-size 41.78125x19.46875 flex-item [BFC] children: not-inline
+        TableWrapper <(anonymous)> at (11,11) content-size 41.78125x19.46875 [BFC] children: not-inline
+          TableBox <(anonymous)> at (11,11) content-size 41.78125x19.46875 [TFC] children: not-inline
             TableRowBox <(anonymous)> at (11,11) content-size 41.78125x19.46875 children: not-inline
-              TableCellBox <div.cell> at (12,12) content-size 39.78125x17.46875 children: inline
+              TableCellBox <div.cell> at (12,12) content-size 39.78125x17.46875 [BFC] children: inline
                 line 0 width: 39.78125, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                   frag 0 from TextNode start: 0, length: 5, rect: [12,12 39.78125x17.46875]
                     "Hello"
diff --git a/Tests/LibWeb/Layout/expected/table/row-px-height.txt b/Tests/LibWeb/Layout/expected/table/row-px-height.txt
index fa68c787f0..f300f37411 100644
--- a/Tests/LibWeb/Layout/expected/table/row-px-height.txt
+++ b/Tests/LibWeb/Layout/expected/table/row-px-height.txt
@@ -1,6 +1,6 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x116 children: not-inline
-    TableWrapper <(anonymous)> at (8,8) content-size 102x100 children: not-inline
-      TableBox <body> at (8,8) content-size 102x100 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x116 [BFC] children: not-inline
+    TableWrapper <(anonymous)> at (8,8) content-size 102x100 [BFC] children: not-inline
+      TableBox <body> at (8,8) content-size 102x100 [TFC] children: not-inline
         TableRowBox <div.row> at (8,8) content-size 102x100 children: not-inline
-          TableCellBox <div.cell> at (9,9) content-size 100x0 children: not-inline
+          TableCellBox <div.cell> at (9,9) content-size 100x0 [BFC] children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/table/rows-height-distribution-1.txt b/Tests/LibWeb/Layout/expected/table/rows-height-distribution-1.txt
index edfe78b7af..c38ac98107 100644
--- a/Tests/LibWeb/Layout/expected/table/rows-height-distribution-1.txt
+++ b/Tests/LibWeb/Layout/expected/table/rows-height-distribution-1.txt
@@ -1,9 +1,9 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x166 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x166 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x150 children: not-inline
-      TableWrapper <(anonymous)> at (8,8) content-size 200x150 children: not-inline
-        TableBox <div.table> at (8,8) content-size 200x150 children: not-inline
+      TableWrapper <(anonymous)> at (8,8) content-size 200x150 [BFC] children: not-inline
+        TableBox <div.table> at (8,8) content-size 200x150 [TFC] children: not-inline
           TableRowBox <div.row.a> at (8,8) content-size 200x50 children: not-inline
-            TableCellBox <div.cell> at (8,8) content-size 200x0 children: not-inline
+            TableCellBox <div.cell> at (8,8) content-size 200x0 [BFC] children: not-inline
           TableRowBox <div.row.b> at (8,58) content-size 200x100 children: not-inline
-            TableCellBox <div.cell> at (8,58) content-size 200x0 children: not-inline
+            TableCellBox <div.cell> at (8,58) content-size 200x0 [BFC] children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/table/rows-height-distribution-2.txt b/Tests/LibWeb/Layout/expected/table/rows-height-distribution-2.txt
index ccd7ce3662..8867d5bb55 100644
--- a/Tests/LibWeb/Layout/expected/table/rows-height-distribution-2.txt
+++ b/Tests/LibWeb/Layout/expected/table/rows-height-distribution-2.txt
@@ -1,9 +1,9 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x316 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x316 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x300 children: not-inline
-      TableWrapper <(anonymous)> at (8,8) content-size 200x300 children: not-inline
-        TableBox <div.table> at (8,8) content-size 200x300 children: not-inline
+      TableWrapper <(anonymous)> at (8,8) content-size 200x300 [BFC] children: not-inline
+        TableBox <div.table> at (8,8) content-size 200x300 [TFC] children: not-inline
           TableRowBox <div.row.a> at (8,8) content-size 200x150 children: not-inline
-            TableCellBox <div.cell> at (8,8) content-size 200x0 children: not-inline
+            TableCellBox <div.cell> at (8,8) content-size 200x0 [BFC] children: not-inline
           TableRowBox <div.row.b> at (8,158) content-size 200x150 children: not-inline
-            TableCellBox <div.cell> at (8,158) content-size 200x0 children: not-inline
+            TableCellBox <div.cell> at (8,158) content-size 200x0 [BFC] children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/table/rows-height-distribution-3.txt b/Tests/LibWeb/Layout/expected/table/rows-height-distribution-3.txt
index 2b7902da0d..e024383a7c 100644
--- a/Tests/LibWeb/Layout/expected/table/rows-height-distribution-3.txt
+++ b/Tests/LibWeb/Layout/expected/table/rows-height-distribution-3.txt
@@ -1,16 +1,16 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x316 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x316 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x300 children: not-inline
-      TableWrapper <(anonymous)> at (8,8) content-size 200x300 children: not-inline
-        TableBox <div.table> at (8,8) content-size 200x300 children: not-inline
+      TableWrapper <(anonymous)> at (8,8) content-size 200x300 [BFC] children: not-inline
+        TableBox <div.table> at (8,8) content-size 200x300 [TFC] children: not-inline
           TableRowBox <div.row.a> at (8,8) content-size 200x150 children: not-inline
-            TableCellBox <div.cell> at (8,8) content-size 200x17.46875 children: inline
+            TableCellBox <div.cell> at (8,8) content-size 200x17.46875 [BFC] children: inline
               line 0 width: 9.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                 frag 0 from TextNode start: 0, length: 1, rect: [8,8 9.34375x17.46875]
                   "a"
               TextNode <#text>
           TableRowBox <div.row.b> at (8,158) content-size 200x150 children: not-inline
-            TableCellBox <div.cell> at (8,158) content-size 200x17.46875 children: inline
+            TableCellBox <div.cell> at (8,158) content-size 200x17.46875 [BFC] children: inline
               line 0 width: 9.46875, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                 frag 0 from TextNode start: 0, length: 1, rect: [8,158 9.46875x17.46875]
                   "b"
diff --git a/Tests/LibWeb/Layout/expected/table/rows-height-distribution-4.txt b/Tests/LibWeb/Layout/expected/table/rows-height-distribution-4.txt
index 36f6d4670b..568a932491 100644
--- a/Tests/LibWeb/Layout/expected/table/rows-height-distribution-4.txt
+++ b/Tests/LibWeb/Layout/expected/table/rows-height-distribution-4.txt
@@ -1,16 +1,16 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x316 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x316 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x300 children: not-inline
-      TableWrapper <(anonymous)> at (8,8) content-size 200x300 children: not-inline
-        TableBox <div.table> at (8,8) content-size 200x300 children: not-inline
+      TableWrapper <(anonymous)> at (8,8) content-size 200x300 [BFC] children: not-inline
+        TableBox <div.table> at (8,8) content-size 200x300 [TFC] children: not-inline
           TableRowBox <div.row.a> at (8,8) content-size 200x100 children: not-inline
-            TableCellBox <div.cell> at (8,8) content-size 200x17.46875 children: inline
+            TableCellBox <div.cell> at (8,8) content-size 200x17.46875 [BFC] children: inline
               line 0 width: 9.34375, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                 frag 0 from TextNode start: 0, length: 1, rect: [8,8 9.34375x17.46875]
                   "a"
               TextNode <#text>
           TableRowBox <div.row.b> at (8,108) content-size 200x200 children: not-inline
-            TableCellBox <div.cell> at (8,108) content-size 200x17.46875 children: inline
+            TableCellBox <div.cell> at (8,108) content-size 200x17.46875 [BFC] children: inline
               line 0 width: 9.46875, height: 17.46875, bottom: 17.46875, baseline: 13.53125
                 frag 0 from TextNode start: 0, length: 1, rect: [8,108 9.46875x17.46875]
                   "b"
diff --git a/Tests/LibWeb/Layout/expected/table/size.txt b/Tests/LibWeb/Layout/expected/table/size.txt
index e67c1421a0..5ec7b29552 100644
--- a/Tests/LibWeb/Layout/expected/table/size.txt
+++ b/Tests/LibWeb/Layout/expected/table/size.txt
@@ -1,10 +1,10 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x33.46875 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x33.46875 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x17.46875 children: not-inline
-      TableWrapper <(anonymous)> at (350,8) content-size 100x17.46875 children: not-inline
-        TableBox <div> at (350,8) content-size 100x17.46875 children: not-inline
+      TableWrapper <(anonymous)> at (350,8) content-size 100x17.46875 [BFC] children: not-inline
+        TableBox <div> at (350,8) content-size 100x17.46875 [TFC] children: not-inline
           TableRowBox <(anonymous)> at (350,8) content-size 2000x17.46875 children: not-inline
-            TableCellBox <(anonymous)> at (350,8) content-size 2000x17.46875 children: not-inline
+            TableCellBox <(anonymous)> at (350,8) content-size 2000x17.46875 [BFC] children: not-inline
               BlockContainer <(anonymous)> at (350,8) content-size 2000x0 children: inline
                 TextNode <#text>
               BlockContainer <div> at (350,8) content-size 2000x17.46875 children: inline
diff --git a/Tests/LibWeb/Layout/expected/table/table-width.txt b/Tests/LibWeb/Layout/expected/table/table-width.txt
index 516f6da781..8f6fe41b4e 100644
--- a/Tests/LibWeb/Layout/expected/table/table-width.txt
+++ b/Tests/LibWeb/Layout/expected/table/table-width.txt
@@ -1,8 +1,8 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x226 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x226 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x210 children: not-inline
-      TableWrapper <(anonymous)> at (8,8) content-size 584x210 children: not-inline
-        TableBox <table.table> at (108,108) content-size 584x10 children: not-inline
+      TableWrapper <(anonymous)> at (8,8) content-size 584x210 [BFC] children: not-inline
+        TableBox <table.table> at (108,108) content-size 584x10 [TFC] children: not-inline
           TableRowGroupBox <tbody> at (108,108) content-size 584x10 children: not-inline
             TableRowBox <tr> at (108,108) content-size 584x10 children: not-inline
-              TableCellBox <td.cell> at (109,113) content-size 582x0 children: not-inline
+              TableCellBox <td.cell> at (109,113) content-size 582x0 [BFC] children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/table/zero-columns-gridmax.txt b/Tests/LibWeb/Layout/expected/table/zero-columns-gridmax.txt
index 22f0923aa2..71ab77e8a6 100644
--- a/Tests/LibWeb/Layout/expected/table/zero-columns-gridmax.txt
+++ b/Tests/LibWeb/Layout/expected/table/zero-columns-gridmax.txt
@@ -1,7 +1,7 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (0,0) content-size 800x16 children: not-inline
+  BlockContainer <html> at (0,0) content-size 800x16 [BFC] children: not-inline
     BlockContainer <body> at (8,8) content-size 784x0 children: not-inline
-      TableWrapper <(anonymous)> at (8,8) content-size 200x0 children: not-inline
-        TableBox <div.table> at (8,8) content-size 200x0 children: not-inline
+      TableWrapper <(anonymous)> at (8,8) content-size 200x0 [BFC] children: not-inline
+        TableBox <div.table> at (8,8) content-size 200x0 [TFC] children: not-inline
           TableRowBox <div.row> at (8,8) content-size 200x0 children: not-inline
-            TableCellBox <div.cell> at (8,8) content-size 200x0 children: not-inline
+            TableCellBox <div.cell> at (8,8) content-size 200x0 [BFC] children: not-inline
diff --git a/Tests/LibWeb/Layout/expected/vertical-padding-relative-to-cb-width.txt b/Tests/LibWeb/Layout/expected/vertical-padding-relative-to-cb-width.txt
index 9979586dc9..1a52252b84 100644
--- a/Tests/LibWeb/Layout/expected/vertical-padding-relative-to-cb-width.txt
+++ b/Tests/LibWeb/Layout/expected/vertical-padding-relative-to-cb-width.txt
@@ -1,5 +1,5 @@
 Viewport <#document> at (0,0) content-size 800x600 children: not-inline
-  BlockContainer <html> at (1,1) content-size 798x30 children: not-inline
+  BlockContainer <html> at (1,1) content-size 798x30 [BFC] children: not-inline
     BlockContainer <body> at (10,10) content-size 780x12 children: not-inline
       BlockContainer <(anonymous)> at (10,10) content-size 780x0 children: inline
         TextNode <#text>
diff --git a/Userland/Libraries/LibWeb/Dump.cpp b/Userland/Libraries/LibWeb/Dump.cpp
index c2b10e6d47..6c594cba1e 100644
--- a/Userland/Libraries/LibWeb/Dump.cpp
+++ b/Userland/Libraries/LibWeb/Dump.cpp
@@ -24,6 +24,7 @@
 #include <LibWeb/Dump.h>
 #include <LibWeb/HTML/HTMLTemplateElement.h>
 #include <LibWeb/Layout/BlockContainer.h>
+#include <LibWeb/Layout/FormattingContext.h>
 #include <LibWeb/Layout/FrameBox.h>
 #include <LibWeb/Layout/Node.h>
 #include <LibWeb/Layout/SVGBox.h>
@@ -128,6 +129,7 @@ void dump_tree(StringBuilder& builder, Layout::Node const& layout_node, bool sho
     StringView line_box_color_on = ""sv;
     StringView fragment_color_on = ""sv;
     StringView flex_color_on = ""sv;
+    StringView formatting_context_color_on = ""sv;
     StringView color_off = ""sv;
 
     if (interactive) {
@@ -140,6 +142,7 @@ void dump_tree(StringBuilder& builder, Layout::Node const& layout_node, bool sho
         line_box_color_on = "\033[34;1m"sv;
         fragment_color_on = "\033[35;1m"sv;
         flex_color_on = "\033[34;1m"sv;
+        formatting_context_color_on = "\033[37;1m"sv;
         color_off = "\033[0m"sv;
     }
 
@@ -225,6 +228,28 @@ void dump_tree(StringBuilder& builder, Layout::Node const& layout_node, bool sho
                 box.box_model().margin.bottom);
         }
 
+        if (auto formatting_context_type = Layout::FormattingContext::formatting_context_type_created_by_box(box); formatting_context_type.has_value()) {
+            switch (formatting_context_type.value()) {
+            case Layout::FormattingContext::Type::Block:
+                builder.appendff(" [{}BFC{}]", formatting_context_color_on, color_off);
+                break;
+            case Layout::FormattingContext::Type::Flex:
+                builder.appendff(" [{}FFC{}]", formatting_context_color_on, color_off);
+                break;
+            case Layout::FormattingContext::Type::Grid:
+                builder.appendff(" [{}GFC{}]", formatting_context_color_on, color_off);
+                break;
+            case Layout::FormattingContext::Type::Table:
+                builder.appendff(" [{}TFC{}]", formatting_context_color_on, color_off);
+                break;
+            case Layout::FormattingContext::Type::SVG:
+                builder.appendff(" [{}SVG{}]", formatting_context_color_on, color_off);
+                break;
+            default:
+                break;
+            }
+        }
+
         builder.appendff(" children: {}", box.children_are_inline() ? "inline" : "not-inline");
 
         if (is<Layout::FrameBox>(box)) {
diff --git a/Userland/Libraries/LibWeb/Layout/FormattingContext.cpp b/Userland/Libraries/LibWeb/Layout/FormattingContext.cpp
index 421643823e..55e3d337c5 100644
--- a/Userland/Libraries/LibWeb/Layout/FormattingContext.cpp
+++ b/Userland/Libraries/LibWeb/Layout/FormattingContext.cpp
@@ -114,74 +114,99 @@ bool FormattingContext::creates_block_formatting_context(Box const& box)
     return false;
 }
 
-OwnPtr<FormattingContext> FormattingContext::create_independent_formatting_context_if_needed(LayoutState& state, Box const& child_box)
+Optional<FormattingContext::Type> FormattingContext::formatting_context_type_created_by_box(Box const& box)
 {
-    if (child_box.is_replaced_box() && !child_box.can_have_children()) {
-        // NOTE: This is a bit strange.
-        //       Basically, we create a pretend formatting context for replaced elements that does nothing.
-        //       This allows other formatting contexts to treat them like elements that actually need inside layout
-        //       without having separate code to handle replaced elements.
-        // FIXME: Find a better abstraction for this.
-        struct ReplacedFormattingContext : public FormattingContext {
-            ReplacedFormattingContext(LayoutState& state, Box const& box)
-                : FormattingContext(Type::Block, state, box)
-            {
-            }
-            virtual CSSPixels automatic_content_width() const override { return 0; }
-            virtual CSSPixels automatic_content_height() const override { return 0; }
-            virtual void run(Box const&, LayoutMode, AvailableSpace const&) override { }
-        };
-        return make<ReplacedFormattingContext>(state, child_box);
+    if (box.is_replaced_box() && !box.can_have_children()) {
+        return Type::InternalReplaced;
     }
 
-    if (!child_box.can_have_children())
+    if (!box.can_have_children())
         return {};
 
-    auto child_display = child_box.display();
+    if (is<SVGSVGBox>(box))
+        return Type::SVG;
 
-    if (is<SVGSVGBox>(child_box))
-        return make<SVGFormattingContext>(state, child_box, this);
+    auto display = box.display();
 
-    if (child_display.is_flex_inside())
-        return make<FlexFormattingContext>(state, child_box, this);
+    if (display.is_flex_inside())
+        return Type::Flex;
 
-    if (creates_block_formatting_context(child_box))
-        return make<BlockFormattingContext>(state, verify_cast<BlockContainer>(child_box), this);
+    if (display.is_table_inside())
+        return Type::Table;
 
-    if (child_display.is_table_inside())
-        return make<TableFormattingContext>(state, verify_cast<TableBox>(child_box), this);
+    if (display.is_grid_inside())
+        return Type::Grid;
 
-    if (child_display.is_grid_inside()) {
-        return make<GridFormattingContext>(state, child_box, this);
-    }
+    if (creates_block_formatting_context(box))
+        return Type::Block;
 
-    VERIFY(is_block_formatting_context());
-    if (child_box.children_are_inline())
+    if (box.children_are_inline())
         return {};
 
-    // The child box is a block container that doesn't create its own BFC.
-    // It will be formatted by this BFC.
-    if (!child_display.is_flow_inside()) {
-        dbgln("FIXME: Child box doesn't create BFC, but inside is also not flow! display={}", MUST(child_display.to_string()));
+    // The box is a block container that doesn't create its own BFC.
+    // It will be formatted by the containing BFC.
+    if (!display.is_flow_inside()) {
         // HACK: Instead of crashing, create a dummy formatting context that does nothing.
         // FIXME: Remove this once it's no longer needed. It currently swallows problem with standalone
         //        table-related boxes that don't get fixed up by CSS anonymous table box generation.
-        struct DummyFormattingContext : public FormattingContext {
-            DummyFormattingContext(LayoutState& state, Box const& box)
-                : FormattingContext(Type::Block, state, box)
-            {
-            }
-            virtual CSSPixels automatic_content_width() const override { return 0; }
-            virtual CSSPixels automatic_content_height() const override { return 0; }
-            virtual void run(Box const&, LayoutMode, AvailableSpace const&) override { }
-        };
-        return make<DummyFormattingContext>(state, child_box);
+        dbgln("FIXME: Child box doesn't create BFC, but inside is also not flow! display={}", MUST(display.to_string()));
+        return Type::InternalDummy;
     }
-    VERIFY(child_box.is_block_container());
-    VERIFY(child_display.is_flow_inside());
     return {};
 }
 
+// FIXME: This is a hack. Get rid of it.
+struct ReplacedFormattingContext : public FormattingContext {
+    ReplacedFormattingContext(LayoutState& state, Box const& box)
+        : FormattingContext(Type::Block, state, box)
+    {
+    }
+    virtual CSSPixels automatic_content_width() const override { return 0; }
+    virtual CSSPixels automatic_content_height() const override { return 0; }
+    virtual void run(Box const&, LayoutMode, AvailableSpace const&) override { }
+};
+
+// FIXME: This is a hack. Get rid of it.
+struct DummyFormattingContext : public FormattingContext {
+    DummyFormattingContext(LayoutState& state, Box const& box)
+        : FormattingContext(Type::Block, state, box)
+    {
+    }
+    virtual CSSPixels automatic_content_width() const override { return 0; }
+    virtual CSSPixels automatic_content_height() const override { return 0; }
+    virtual void run(Box const&, LayoutMode, AvailableSpace const&) override { }
+};
+
+OwnPtr<FormattingContext> FormattingContext::create_independent_formatting_context_if_needed(LayoutState& state, Box const& child_box)
+{
+    auto type = formatting_context_type_created_by_box(child_box);
+    if (!type.has_value())
+        return nullptr;
+
+    switch (type.value()) {
+    case Type::Block:
+        return make<BlockFormattingContext>(state, verify_cast<BlockContainer>(child_box), this);
+    case Type::SVG:
+        return make<SVGFormattingContext>(state, child_box, this);
+    case Type::Flex:
+        return make<FlexFormattingContext>(state, child_box, this);
+    case Type::Grid:
+        return make<GridFormattingContext>(state, child_box, this);
+    case Type::Table:
+        return make<TableFormattingContext>(state, verify_cast<TableBox>(child_box), this);
+    case Type::InternalReplaced:
+        return make<ReplacedFormattingContext>(state, child_box);
+    case Type::InternalDummy:
+        return make<DummyFormattingContext>(state, child_box);
+    case Type::Inline:
+        // IFC should always be created by a parent BFC directly.
+        VERIFY_NOT_REACHED();
+        break;
+    default:
+        VERIFY_NOT_REACHED();
+    }
+}
+
 OwnPtr<FormattingContext> FormattingContext::layout_inside(Box const& child_box, LayoutMode layout_mode, AvailableSpace const& available_space)
 {
     {
diff --git a/Userland/Libraries/LibWeb/Layout/FormattingContext.h b/Userland/Libraries/LibWeb/Layout/FormattingContext.h
index 378d99f72e..c203db9479 100644
--- a/Userland/Libraries/LibWeb/Layout/FormattingContext.h
+++ b/Userland/Libraries/LibWeb/Layout/FormattingContext.h
@@ -24,6 +24,8 @@ public:
         Grid,
         Table,
         SVG,
+        InternalReplaced, // Internal hack formatting context for replaced elements. FIXME: Get rid of this.
+        InternalDummy,    // Internal hack formatting context for unimplemented things. FIXME: Get rid of this.
     };
 
     virtual void run(Box const&, LayoutMode, AvailableSpace const&) = 0;
@@ -44,6 +46,8 @@ public:
 
     virtual bool inhibits_floating() const { return false; }
 
+    [[nodiscard]] static Optional<Type> formatting_context_type_created_by_box(Box const&);
+
     static bool creates_block_formatting_context(Box const&);
 
     static CSSPixels compute_width_for_replaced_element(LayoutState const&, ReplacedBox const&, AvailableSpace const&);
