Wrapped the expanded r-g grammar in a note, added more explanation of why it exists.

Author: tabatkins

css3-images/Overview.html

@@ -976,10 +976,16 @@ <h4 class=no-toc id=radial-gradient-syntax><span class=secno>5.2.1. </span>
     </dl>
   </dl>
 
-  <p>The expanded grammar for &lsquo;<code
-   class=css>radial-gradient()</code>&rsquo; is thus:
+  <div class=note>
+   <p>The grammar listed above is kept deliberately simple for readability
+    purposes, with some details instead expressed in the prose. All of the
+    details can be expressed directly in the grammar, however, and such a
+    grammar is presented here for use by implementors and others writing
+    parsers. It is officially non-normative, but should match the same set of
+    strings that the normative grammar does when augmented with the prose.
 
-  <pre>&lt;radial-gradient> = radial-gradient(
+   <pre>
+&lt;radial-gradient> = radial-gradient(
   [ [ circle | ellipse ]  , |
     [ circle | ellipse ]? [ at &lt;position> || to &lt;extent-keyword> ] , |
     circle?               [ at &lt;position> || to &lt;length> ] , |
@@ -988,6 +994,7 @@ <h4 class=no-toc id=radial-gradient-syntax><span class=secno>5.2.1. </span>
   &lt;color-stop> [ , &lt;color-stop> ]+
 )
 &lt;extent-keyword> = closest-corner | closest-side | farthest-corner | farthest-side</pre>
+  </div>
 
   <h4 class=no-toc id=radial-color-stops><span class=secno>5.2.2. </span>
    Placing Color Stops</h4>

css3-images/Overview.src.html

@@ -629,8 +629,11 @@ <h4 class='no-toc' id='radial-gradient-syntax'>
 		</dd>
 	</dl>
 
-  <p>The expanded grammar for ''radial-gradient()'' is thus:
-<pre>&lt;radial-gradient> = radial-gradient(
+	<div class='note'>
+		<p>The grammar listed above is kept deliberately simple for readability purposes, with some details instead expressed in the prose.  All of the details can be expressed directly in the grammar, however, and such a grammar is presented here for use by implementors and others writing parsers.  It is officially non-normative, but should match the same set of strings that the normative grammar does when augmented with the prose.
+
+		<pre>
+&lt;radial-gradient> = radial-gradient(
   [ [ circle | ellipse ]  , |
     [ circle | ellipse ]? [ at &lt;position> || to &lt;extent-keyword> ] , |
     circle?               [ at &lt;position> || to &lt;length> ] , |
@@ -639,6 +642,7 @@ <h4 class='no-toc' id='radial-gradient-syntax'>
   &lt;color-stop> [ , &lt;color-stop> ]+
 )
 &lt;extent-keyword> = closest-corner | closest-side | farthest-corner | farthest-side</pre>
+	</div>
 
 <h4 class="no-toc" id="radial-color-stops">
 Placing Color Stops</h4>