[css-lists] Add issue about counter-value().

Author: tabatkins

css-lists/Overview.bs

@@ -1265,6 +1265,29 @@ Printing Counters: the ''counter()'' and ''counters()'' functions</h2>
 		</pre>
 	</div>
 
+	<div class=issue>
+		Counters are sometimes useful for things other than printing markers.
+		In general, they provide the ability to number elements in sequence,
+		which can be useful for other properties to reference.
+		For example, using 'order' to put an element between two other specific elements
+		currently requires you to explicitly put 'order' on every element before and/or after the desired insertion point.
+		If you can set the 'order' value of everything to a counter, tho,
+		you can more easily insert an element into an arbitrary spot between two others.
+
+		Other use-cases involve nested or sibling elements with transforms that are meant to be slightly different from each other.
+		Today you have to use a preprocessor to do this in a reasonable way,
+		but a counter would make it work well in "plain" CSS.
+
+		(You can built up successive values in the nested case today
+		by using <a>custom properties</a> and stacking up nested ''calc()''s,
+		but this is a *little bit* clumsy,
+		and doesn't work for siblings.)
+
+		Suggestion is to add a <css>counter-value(<<ident>>)</css> function,
+		which returns the value of the named counter as an integer,
+		rather than returning a string.
+	</div>
+
 
 
 <h2 id='ua-stylesheet'>