[css-fonts] tweak syntax description for @font-feature-values rule

Author: John Daggett

css-fonts/Fonts.html

@@ -112,15 +112,15 @@
 
    <h1>CSS Fonts Module Level 3</h1>
 
-   <h2 class="no-num no-toc" id=editors-draft-7-may-2013>Editor's Draft 7 May
+   <h2 class="no-num no-toc" id=editors-draft-8-may-2013>Editor's Draft 8 May
     2013</h2>
 
    <dl id=authors>
     <dt>This version:
 
     <dd><a
      href="http://dev.w3.org/csswg/css-fonts/">http://dev.w3.org/csswg/css-fonts/</a>
-     <!-- <dd><a href="http://www.w3.org/TR/2013/ED-css3-fonts-20130507/">http://www.w3.org/TR/2013/ED-css3-fonts-20130507/</a> -->
+     <!-- <dd><a href="http://www.w3.org/TR/2013/ED-css3-fonts-20130508/">http://www.w3.org/TR/2013/ED-css3-fonts-20130508/</a> -->
 
 
     <dt>Latest version:
@@ -4334,10 +4334,16 @@ <h3 id=font-feature-values><span class=secno>6.9 </span>Defining font
   <pre>@{F}{O}{N}{T}{-}{F}{E}{A}{T}{U}{R}{E}{-}{V}{A}{L}{U}{E}{S}   {return FONT_FEATURE_VALUES_SYM;}
 </pre>
 
-  <p>These rules define a set of values for a specific font feature as used
-   for a given set of families. Effectively, they define a mapping of
-   ⟨family, feature, ident⟩ → ⟨values⟩ where ⟨values⟩ are the
-   indices used for specific features defined for a given font.
+  <p>Feature value blocks are treated <a
+   href="http://www.w3.org/TR/CSS2/syndata.html#at-rules">similar to
+   at-rules</a>, they consist of everything up to the next block or
+   semi-colon, whichever comes first.
+
+  <p>Font feature values rules define a set of values for a specific font
+   feature as used for a given set of families. Effectively, they define a
+   mapping of ⟨family, feature, ident⟩ → ⟨values⟩ where
+   ⟨values⟩ are the indices used for specific features defined for a
+   given font.
 
   <p>The font family list uses the same syntax as that used for the ‘<a
    href="#descdef-font-family"><code class=property>font-family</code></a>’