[css-text-4] Allow UA to truncate hyphenation character. #2810

Author: fantasai

css-text-4/Overview.bs

@@ -548,6 +548,12 @@ Hyphens: the 'hyphenate-character' property</h3>
 		<dd>
 			Specifies the string that appears
 			at the end of the line before a hyphenation break.
+			The UA <em>may</em> truncate the <!-- computed value | used value --> string
+			to a single <a>typographic character unit</a>.
+<!-- alternately:
+			to a limited number of <a>typographic character units</a>.
+			(It must not truncate only part of a <a>typographic character unit</a>.)
+-->
 	</dl>
 
 	<div class="example">