clarify if -> iff for margin box instantiation

Author: fantasai

css3-page/Overview.html

@@ -87,14 +87,14 @@
 
     <h1>CSS Paged Media Module Level 3</h1>
 
-    <h2 class="no-num no-toc" id=w3c-working>Editor's Draft 28 March 2009</h2>
+    <h2 class="no-num no-toc" id=w3c-working>Editor's Draft 8 April 2009</h2>
 
     <dl>
      <dt>This version:
 
      <dd><a
       href="http://dev.w3.org/csswg/css3-page/">http://dev.w3.org/csswg/css3-page/</a></dd>
-     <!-- <dd><a href="http://www.w3.org/TR/2009/ED-css3-page-20090328">http://www.w3.org/TR/2009/WD-css3-page-20090328</a></dd> -->
+     <!-- <dd><a href="http://www.w3.org/TR/2009/ED-css3-page-20090408">http://www.w3.org/TR/2009/WD-css3-page-20090408</a></dd> -->
 
      <dt>Latest version:
 
@@ -179,8 +179,8 @@ <h2 class="no-num no-toc" id=status>Status of this Document</h2>
    <!--end-status-->
    <p>This document contains the <abbr title="Cascading Style
     Sheets">CSS3</abbr> Paged Media Module W3C Last Call <a
-    href="/2005/10/Process-20051014/tr.html#RecsWD">Working Draft</a> of 28
-    March 2009. The Last Call period ends on <span class=fudge>TBD</span>.</p>
+    href="/2005/10/Process-20051014/tr.html#RecsWD">Working Draft</a> of 8
+    April 2009. The Last Call period ends on <span class=fudge>TBD</span>.</p>
 
    <p>Relative to the previous Last Call Working Draft, this version
     incorporates changes to the formerly named &lsquo;<code
@@ -1284,9 +1284,9 @@ <h3 id=margin-at-rules><span class=secno>6.1 </span>At-rules for margin
    <h3 id=populating-margin-boxes><span class=secno>6.2 </span>Populating
     margin boxes</h3>
 
-   <p>A margin box is instantiated if the computed value of its &lsquo;<code
-    class=property>content</code>&rsquo; property does not match that of its
-    initial value.
+   <p>A margin box is instantiated if and only if the computed value of its
+    &lsquo;<code class=property>content</code>&rsquo; property does not match
+    that of its initial value.
 
    <div class=example>
     <p>The following style sheet creates a green box in each corner of the

css3-page/Overview.src.html

@@ -889,7 +889,7 @@ <h3 id="margin-at-rules">At-rules for margin boxes</h3>
 
 <h3 id="populating-margin-boxes">Populating margin boxes</h3>
 
-<p>A margin box is instantiated if the computed value of its
+<p>A margin box is instantiated if and only if the computed value of its
 'content' property does not match that of its initial value.
 
 <div class="example">