[css-ruby] autohiding is disabled if ruby-merge: collapse <https://lists.w3.org/Archives/Public/www-style/2015Feb/0354.html>

Author: Koji Ishii

css-ruby/Overview.bs

@@ -572,10 +572,11 @@ Autohiding Base-identical Annotations</h3>
 	</div>
 
 	<p>When the computed value of 'ruby-merge' is ''collapse'',
-	then all annotations and bases for that segment are compared
-	(rather than just each annotation and its base individually)
-	and the annotation for the entire segment
-	is either hidden or shown as appropriate.
+	the autohiding is disabled.
+	When the computed value of 'ruby-merge' is ''auto'',
+	the user agent may decide whether to autohide or not,
+	but it is recommended to autohide if the algorithm the user agent chose
+	produces the results similar to ''separate'' would produce.
 
 	<p>The content comparison for this auto-hiding behavior
 	takes place prior to white space collapsing ('white-space') and text transformation ('text-transform')