Added reference to percentage in css3-value. Added issue about

stretching margins for distributing blocks vertically.

Author: bert-github

css3-box/Overview.src.html

@@ -137,6 +137,7 @@ <h2>Dependencies on other modules</h2>
     properties and values
   <li><cite>CSS Values and Units Module</cite> [[!CSS3VAL]] &ndash;
     definitions of value types <dfn><var>&lt;number&gt;</var></dfn>,
+    <dfn><var>&lt;percentage&gt;</var></dfn>,
     <dfn><var>&lt;angle&gt;</var></dfn> and
     <dfn><var>&lt;length&gt;</var></dfn>; defines the terms <dfn>computed
     value</dfn> and <dfn>used value.</dfn>
@@ -1501,6 +1502,14 @@ <h3>The margin properties</h3>
     block</em> is <em>horizontal,</em> otherwise the height
 </table>
 
+<div class=issue>
+<p>Add a stretch value to allow vertical distribution of blocks in a
+fixed-height containing block? css3-flexbox currently (May 2012)
+proposes to use ''auto'', but in normal flow we need something else,
+because ''auto'' already means ''0'' there.
+
+<pre class=prod><var>&lt;stretch&gt;</var> = fill( [ <var>&lt;length&gt;</var>  | <var>&lt;percentage&gt;</var> ] )</pre>
+</div>
 <p>These properties set the thickness of the <em>margin area</em>. The value
 may be negative.