caption box is optional

Author: annevk

cssom-view/Overview.html

@@ -568,7 +568,7 @@ <h3 id=the-getclientrects><span class=secno>6.1 </span>The <code
       <p>If the element on which the method was invoked has a computed value
        for <code>display</code> property of <code>table</code> or
        <code>inline-table</code> include both the table box and the caption
-       box, but not the anonymous container box. [<cite><a
+       box, if any, but not the anonymous container box. [<cite><a
        href="#ref-css21">CSS21</a></cite>]
 
      <li>

cssom-view/Overview.src.html

@@ -450,7 +450,7 @@ <h3>The <code title="">getClientRects()</code> and
      <li><p>If the element on which the method was invoked has a computed
      value for <code>display</code> property of <code>table</code> or
      <code>inline-table</code> include both the table box and the caption
-     box, but not the anonymous container box.
+     box, if any, but not the anonymous container box.
      [<cite><span>CSS21</span></cite>]</p></li>
 
      <li><p>Replace each