[css-writing-modes-3] s/this level/this specification/ w3c#4231

Author: fantasai

css-writing-modes-3/Overview.bs

@@ -2050,8 +2050,9 @@ Auto-sizing Orthogonal Flow Roots</h4>
   The [=automatic sizing=] of orthogonal [=multi-column containers=]
   (in both axes)
   and of other [=display types=] not mentioned above
-  is undefined in this level;
-  see <a href="https://www.w3.org/TR/css-writing-modes-4/#auto-multicol">CSS Writing Modes Level 4</a>.
+  is undefined in this specification.
+
+  Note: See <a href="https://www.w3.org/TR/css-writing-modes-4/#auto-multicol">CSS Writing Modes Level 4</a>.
 
 <h4 id="orthogonal-pagination">
 Fragmenting Orthogonal Flows</h4>