[css-variables] Disallow top-level '\!' characters as well.

Author: tabatkins

css-variables/Overview.html

@@ -225,10 +225,10 @@ <h2 id="introduction" data-level="1"><span class="secno">1 </span>
 <p>	The allowed syntax for <a data-autolink="link" href="#custom-property">custom properties</a> is extremely permissive.
 	The <dfn id="any-value-production">&lt;any-value&gt;</dfn> production matches <em>any</em> sequence of one or more tokens,
 	so long as the sequence does not contain
-	<a data-autolink="link" class="production"><var>&lt;bad-string&gt;</var></a>, 
-	<a data-autolink="link" class="production"><var>&lt;bad-url&gt;</var></a>, 
+	<a data-autolink="link" class="production"><var>&lt;bad-string&gt;</var></a>,
+	<a data-autolink="link" class="production"><var>&lt;bad-url&gt;</var></a>,
 	unmatched &lt;&lt;)&gt;&gt;, &lt;&lt;]&gt;&gt;, or &lt;&lt;}&gt;&gt;,
-	or top-level <a data-autolink="link" class="production"><var>&lt;semicolon&gt;</var></a> tokens.
+	or top-level <a data-autolink="link" class="production"><var>&lt;semicolon&gt;</var></a> tokens or <a data-autolink="link" class="production"><var>&lt;delim&gt;</var></a> tokens with a value of "!".
 
 </p><p class="note">	Note: This definition,
 	along with the general CSS syntax rules,
@@ -240,6 +240,9 @@ <h2 id="introduction" data-level="1"><span class="secno">1 </span>
 </p><p class="note">	Note: Custom properties can contain a trailing <span data-autolink="maybe" class="css">!important</span>,
 	but this is automatically removed from the property's value by the CSS parser,
 	and makes the custom property "important" in the CSS cascade.
+	In other words, the prohibition on top-level "!" characters
+	does not prevent <span data-autolink="maybe" class="css">!important</span> from being used,
+	as the <span data-autolink="maybe" class="css">!important</span> is removed before syntax checking happens.
 
 </p><p class="note">	Note: While <a data-autolink="link" class="production" href="#any-value-production"><var>&lt;any-value&gt;</var></a> must represent at least one token,
 	that one token may be whitespace.
@@ -937,7 +940,7 @@ <h3 class="no-ref" id="testing">
 
 <h3 id="normative" class="no-num no-ref">
 Normative References</h3>
-<div data-fill-with="normative-references"><dl><dt id="rfc2119" title="RFC2119">[RFC2119]</dt><dd>S. Bradner. <a href="http://www.ietf.org/rfc/rfc2119.txt">Key words for use in RFCs to Indicate Requirement Levels</a>. URL: <a href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a></dd><dt id="css21" title="CSS21">[CSS21]</dt><dd>Bert Bos; et al. <a href="http://www.w3.org/TR/2011/REC-CSS2-20110607/">Cascading Style Sheets Level 2 Revision 1 (CSS 2.1) Specification</a>. 7 June 2011. W3C Recommendation. URL: <a href="http://www.w3.org/TR/2011/REC-CSS2-20110607/">http://www.w3.org/TR/2011/REC-CSS2-20110607/</a></dd></dl></div>
+<div data-fill-with="normative-references"><dl><dt id="css21" title="CSS21">[CSS21]</dt><dd>Bert Bos; et al. <a href="http://www.w3.org/TR/2011/REC-CSS2-20110607/">Cascading Style Sheets Level 2 Revision 1 (CSS 2.1) Specification</a>. 7 June 2011. W3C Recommendation. URL: <a href="http://www.w3.org/TR/2011/REC-CSS2-20110607/">http://www.w3.org/TR/2011/REC-CSS2-20110607/</a></dd><dt id="rfc2119" title="RFC2119">[RFC2119]</dt><dd>S. Bradner. <a href="http://www.ietf.org/rfc/rfc2119.txt">Key words for use in RFCs to Indicate Requirement Levels</a>. URL: <a href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a></dd></dl></div>
 
 <h3 id="informative" class="no-num no-ref">
 Informative References</h3>

css-variables/Overview.src.html

@@ -155,10 +155,10 @@ <h2 id='defining-variables'>
 	The allowed syntax for <a>custom properties</a> is extremely permissive.
 	The <dfn>&lt;any-value></dfn> production matches <em>any</em> sequence of one or more tokens,
 	so long as the sequence does not contain
-	<<bad-string>>, 
-	<<bad-url>>, 
+	<<bad-string>>,
+	<<bad-url>>,
 	unmatched <<)>>, <<]>>, or <<}>>,
-	or top-level <<semicolon>> tokens.
+	or top-level <<semicolon>> tokens or <<delim>> tokens with a value of "!".
 
 	Note: This definition,
 	along with the general CSS syntax rules,
@@ -170,6 +170,9 @@ <h2 id='defining-variables'>
 	Note: Custom properties can contain a trailing ''!important'',
 	but this is automatically removed from the property's value by the CSS parser,
 	and makes the custom property "important" in the CSS cascade.
+	In other words, the prohibition on top-level "!" characters
+	does not prevent ''!important'' from being used,
+	as the ''!important'' is removed before syntax checking happens.
 
 	Note: While <<any-value>> must represent at least one token,
 	that one token may be whitespace.