[css-syntax] Recommend that newer document types not provide an environment encoding.

Author: tabatkins

css-syntax/Overview.html

@@ -464,10 +464,6 @@ <h3 class="heading settled heading" data-level=3.2 id=input-byte-stream><span cl
 				where the "…" is the sequence of bytes corresponding to the encoding’s label.
 			</details>
 
-<p>			UAs may impose an arbitrary limit upon the number of <code>XX</code> bytes scanned,
-			as long as it is large enough to encompass all of the <a href=http://encoding.spec.whatwg.org/#label>labels</a> defined in <a data-biblio-type=normative data-link-type=biblio href=#encoding title=encoding>[ENCODING]</a>;
-			at the time of writing this specification these are all 19 or fewer bytes long.
-
 <p>			If the return value was <code>utf-16be</code> or <code>utf-16le</code>,
 			use <code>utf-8</code> as the fallback encoding;
 			if it was anything else except failure,
@@ -500,6 +496,11 @@ <h3 class="heading settled heading" data-level=3.2 id=input-byte-stream><span cl
 			Otherwise, if an <a data-link-type=dfn href=#environment-encoding0 title="environment encoding">environment encoding</a> is provided by the referring document,
 			use that as the fallback encoding.
 
+<p>			Note that the concept of <a data-link-type=dfn href=#environment-encoding0 title="environment encoding">environment encoding</a> is required for legacy purposes
+			for HTML and XML.
+			New types of referring documents <strong>should not</strong> provide an <a data-link-type=dfn href=#environment-encoding0 title="environment encoding">environment encoding</a>,
+			so the stylesheet defaults to UTF-8 instead in the absence of more explicit information.
+
 		<li>
 			Otherwise, use <code>utf-8</code> as the fallback encoding.
 	</ol>

css-syntax/Overview.src.html

@@ -334,6 +334,11 @@ <h3 id="input-byte-stream">
 			Otherwise, if an <a>environment encoding</a> is provided by the referring document,
 			use that as the fallback encoding.
 
+			Note that the concept of <a>environment encoding</a> is required for legacy purposes
+			for HTML and XML.
+			New types of referring documents <strong>should not</strong> provide an <a>environment encoding</a>,
+			so the stylesheet defaults to UTF-8 instead in the absence of more explicit information.
+
 		<li>
 			Otherwise, use <code>utf-8</code> as the fallback encoding.
 	</ol>