-		Name: column-rule-edge-inset-start, column-rule-edge-inset-end, column-rule-interior-inset-start, column-rule-interior-inset-end, row-rule-edge-inset-start, row-rule-edge-inset-end, row-rule-interior-inset-start, row-rule-interior-inset-end
+		Name: column-rule-inset-cap-start, column-rule-inset-cap-end, column-rule-inset-junction-start, column-rule-inset-junction-end, row-rule-inset-cap-start, row-rule-inset-cap-end, row-rule-inset-junction-start, row-rule-inset-junction-end
 		Value: <>
 		Initial: ''0''
 		Applies to: grid containers, flex containers, multicol containers, and grid lanes containers
@@ -847,18 +847,82 @@ Adjusting gap decoration endpoints: The 'rule-inset' properties
 	These properties can be used to offset the start and end points of gap decorations relative to the
 	segment endpoints which would normally determine where decorations start and end.
 
-	
An edge segment endpoint is any [=segment endpoint=] created at the content edges of the container.
-	
An interior segment endpoint is any [=segment endpoint=] created at a [=gap junction=].
+	[=Gap decorations=] are divided into [=gap decoration segments=] at [=gap junctions=].
+	Once [=gap decoration segments=] have been determined, each [=segment endpoint=] can be classified
+	according to whether its segment joins with another [=gap decoration segment=] at that
+	location. The inset properties below are defined based on this classification:
+
+	

+		A cap segment endpoint is any [=segment endpoint=] whose [=gap decoration segment=]
+		cannot join with any other [=gap decoration segment=] at that location.
+		This includes endpoints at the container's content edges,
+		as well as endpoints left dangling at a [=gap junction=] because no corresponding [=gap decoration segment=]
+		exists to join with due to 'rule-break' or 'rule-visibility-items' properties.
+	
+
+	

+		A junction segment endpoint is any [=segment endpoint=] whose [=gap decoration segment=] can join
+		with one or more other [=gap decoration segments=] at the same [=gap junction=].
+	
+
+
+	

+		
+			.simple-grid {
+				rule-break: intersection;
+				rule-visibility-items: between;
+			}
+		
+		

+			
+			
+		
+	
+
+	

+		
+			.simple-grid-with-empty-cells {
+				rule-break: intersection;
+				rule-visibility-items: between;
+			}
+		
+		

+			
+			
+		
+	
+
+	

+		
+			.donut-grid-layout {
+				rule-break: intersection;
+				rule-visibility-items: between;
+			}
+		
+		

+			
+			
+		
+	
 
 	Percentages are resolved against the crossing gap width, defined as follows:
 	

 		

-			Edge segment endpoints
+			Segment endpoints that coincide with the edge of the container
 		

 			The [=crossing gap width=] is ''0''.
 
 		

-			Interior segment endpoints
+			Segment endpoints that are within the container 
 		

 			The [=crossing gap width=] is the size of the [=gap junction=]
 			in the same dimension as the [=gap=] in which the [=segment endpoint=] lies
@@ -873,13 +937,13 @@ Adjusting gap decoration endpoints: The 'rule-inset' properties
 	
 
 	

-		The 'column-rule-edge-inset-start' and 'row-rule-edge-inset-start' properties apply to [=start segment endpoints=] that are [=edge segment endpoints=].
-		The 'column-rule-interior-inset-start' and 'row-rule-interior-inset-start' properties apply to [=start segment endpoints=] that are [=interior segment endpoints=].
+		The 'column-rule-inset-cap-start' and 'row-rule-inset-cap-start' properties apply to [=start segment endpoints=] that are [=cap segment endpoints=].
+		The 'column-rule-inset-junction-start' and 'row-rule-inset-junction-start' properties apply to [=start segment endpoints=] that are [=junction segment endpoints=].
 		For these properties, positive values offset in the [=end=] direction, and negative values offset in the [=start=] direction, along the axis of the gap.
 	
 	

-		The 'column-rule-edge-inset-end' and 'row-rule-edge-inset-end' properties apply to [=end segment endpoints=] that are [=edge segment endpoints=].
-		The 'column-rule-interior-inset-end' and 'row-rule-interior-inset-end' properties apply to [=end segment endpoints=] that are [=interior segment endpoints=].
+		The 'column-rule-inset-cap-end' and 'row-rule-inset-cap-end' properties apply to [=end segment endpoints=] that are [=cap segment endpoints=].
+		The 'column-rule-inset-junction-end' and 'row-rule-inset-junction-end' properties apply to [=end segment endpoints=] that are [=junction segment endpoints=].
 		For these properties, positive values offset in the [=start=] direction, and negative values offset in the [=end=] direction, along the axis of the gap.
 	
 
@@ -901,10 +965,10 @@ Adjusting gap decoration endpoints: The 'rule-inset' properties
 	
 
 	
-		parsing/rule-edge-start-end-inset-computed.html
-		parsing/rule-edge-start-end-inset-invalid.html
-		parsing/rule-interior-start-end-inset-computed.html
-		parsing/rule-interior-start-end-inset-invalid.html
+		parsing/rule-inset-cap-start-end-computed.html
+		parsing/rule-inset-cap-start-end-invalid.html
+		parsing/rule-inset-junction-start-end-computed.html
+		parsing/rule-inset-junction-start-end-invalid.html
 		flex/flex-gap-decorations-011.html
 		flex/flex-gap-decorations-013.html
 		flex/flex-gap-decorations-014.html
@@ -960,7 +1024,7 @@ Adjusting gap decoration endpoints: The 'rule-inset' properties
 			}
 		

- +

Updated edge and interior insets to be cap and junction insets. + (Issue 13697)

@@ -2452,6 +2448,4 @@ Changes since the 1

Refreshed examples to reflect changes to the specification.

Added links to WPT suite.

Added Acknowledgements section. -

Updated edge and interior insets to be cap and junction insets. - (Issue 13697) From 33c0f88c18773a126b84e8bba08a7d541242f5e7 Mon Sep 17 00:00:00 2001 From: "Sam Davis Omekara (from Dev Box)" Date: Mon, 27 Apr 2026 19:42:05 -0700 Subject: [PATCH 4/7] nit --- css-gaps-1/Overview.bs | 5 +++-- ...ction.png => example-column-inset-start-end.png} | Bin 2 files changed, 3 insertions(+), 2 deletions(-) rename css-gaps-1/images/{example-column-start-end-inset-cap-junction.png => example-column-inset-start-end.png} (100%) diff --git a/css-gaps-1/Overview.bs b/css-gaps-1/Overview.bs index 79bd93589599..d173c8dff66b 100644 --- a/css-gaps-1/Overview.bs +++ b/css-gaps-1/Overview.bs @@ -903,7 +903,8 @@ Adjusting gap decoration endpoints: The 'rule-inset' properties

@@ -1018,7 +1019,7 @@ Adjusting gap decoration endpoints: The 'rule-inset' properties }

- +