[css-inline-3] Define text-box-trim at fragmentation breaks. w3c#5335

Author: fantasai

css-inline-3/Overview.bs

@@ -1476,6 +1476,15 @@ Trimming Over/Under Text: the 'text-box-trim' property</h3>
 
 	ISSUE(11363): What happens if the column is split by a spanner?
 
+	When the box to which 'text-box-trim' has been applied
+	is split by [=fragmentation=] [[!CSS-BREAK-3]],
+	whether trimming is applied per fragment
+	or only to the start/end edges of its first/last fragments
+	is determined by 'box-decoration-break'.
+
+	If, when printing, trimming a [=line box=] would cause its content to be clipped,
+	the UA may ignore 'text-box-trim' on that edge of that [=line box=].
+
 <h3 id="text-box-edge">
 Text Trimming Metrics: the 'text-box-edge' property</h3>
 
@@ -3069,6 +3078,8 @@ Changes</h2>
 		<li>Made 'text-box-edge' inherit; 'text-box-trim' references
 			the relevant value applied to the affected line box(es).
 			(<a href="https://github.com/w3c/csswg-drafts/issues/10904">Issue 10904</a>)
+		<li>Defined behavior of 'text-box-trim' at [=fragmentation=] breaks.
+			(<a href="https://github.com/w3c/csswg-drafts/issues/5335">Issue 5335</a>)
 		<li>Defined behavior of 'text-box-trim' on [=multi-column containers=],
 			and clarified its application to (and through) other formatting contexts.
 			(<a href="https://github.com/w3c/csswg-drafts/issues/5335">Issue 5335</a>,