[css-ui] permissive position of text-overflow: ellipsis

Backport 3123deb from css-overflow-4 to
css-ui-3 as a candidate correction.

See #10418

Author: frivoal

css-ui-3/Overview.bs

@@ -935,6 +935,23 @@ atomic inline-level elements</a>
 at the <a>end</a> edge of the line as necessary to fit the ellipsis, and
 place the ellipsis immediately adjacent
 to the <a>end</a> edge of the remaining inline content.
+
+<div class="candidate correction" id=c5>
+	<span class=marker>Candidate Correction 5:</span>
+	Relax the positioning requirement for the ellipsis
+	based on implementation experience.
+
+	<blockquote>
+		<ins>
+		In order to avoid jitter in the position of the ellipsis
+		as scrolling reveals more content,
+		user agents may adjust the position of the ellipsis
+		to be adjacent to the end of the line,
+		or may fade/hide the ellipsis during scrolling.
+		</ins>
+	</blockquote>
+</div>
+
 The first character or
 <a href="https://www.w3.org/TR/CSS2/visuren.html#inline-boxes">
 atomic inline-level element</a>
@@ -1832,7 +1849,9 @@ This appendix is <em>informative</em>.
 Changes from the <a href="https://www.w3.org/TR/2026/REC-css-ui-3-20260407/">7 April 2026 Recommendation (REC)</a></h3>
 
 <ul>
-	<li><em>none</em></li>
+	<li><a href=#c5>Candidate Correction 5:</a>
+		Relax the positioning requirement for the ellipsis
+		based on implementation experience.
 </ul>