add implementation tier clarification

css-counter-styles-3/Overview.bs

@@ -2034,17 +2034,16 @@ Longhand East Asian Counter Styles</h3>
 		</table>
 	</div>
 
-	Because opinions differ on how best to represent numbers 10k or greater
-	using the longhand CJK styles,
-	all of the counter styles defined in this section are defined to have a range of -9999 to 9999,
-	but implementations may support a larger range.
-	Outside the implementation-supported range,
-	the fallback is ''cjk-decimal''.
-
-	Note: Implementations are encouraged to research and implement counter representations beyond 10k
-	and report back to the CSS Working Group with data
-	when a generally-accepted answer is discovered.
-	Some previous research on this topic is contained in an <a href="https://www.w3.org/TR/2013/WD-css-counter-styles-3-20130718/#extended-cjk">earlier draft</a>.
+	Because opinions differ on how best to represent numbers 10,000 or greater 
+	using the longhand CJK styles, the implementation details are split into two sections. 
+	The Korean and Japanese variants of these counter styles can, if limited to the range 
+	of -9999 to 9999, be expressed as <code>@counter-style</code> rules. 
+	The Chinese variants use a [=Chinese|specialized algorithm=], regardless of range. 
+	The required implementation is described in [[#limited-range-required]], which defines 
+	the styles over these limited ranges, and the optional implementation is described in 
+	[[#extended-range-optional]], which defines them over a larger range following custom algorithms. 
+	Outside the implementation-supported range, 
+	the fallback is 'cjk-decimal'.
 
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