--- a/model/ProvenanceModel.html	Wed Aug 03 15:02:43 2011 +0100
+++ b/model/ProvenanceModel.html	Wed Aug 03 15:57:54 2011 +0100
@@ -863,7 +863,7 @@
 <section id="concept-Revision">
 <h3>Revision</h3>
 
-<p> <dfn id="dfn-Revision">Revision</dfn> represents the creation of a characterized thing considered to be a variant of another. </p>
+<p> <dfn id="dfn-Revision">Revision</dfn> represents the creation of a characterized thing considered to be a variant of another. Deciding whether something is made available as a revision of something else usually involves an agent who is responsible for declaring that the former is variant of the latter. </p>
 
 <p>An assertion isRevisionOf, noted <b>isRevisionOf(b2,b1,ag)</b>:
 <ul>
@@ -887,9 +887,15 @@
 </ul>
 </p>
 
+<p><b>isRevisionOf</b> is a strict sub-relation
+ of <b>isDerivedFrom</b> since two entities <b>e2</b> and <b>e1</b>
+ may satisfy <b>isDerivedFrom(e2,e1)</b> without being a variant of
+ each other.
+</p>
+
 <div class='issue'>Revision should be a class not a  property. This is <a href="http://www.w3.org/2011/prov/track/issues/48">ISSUE-48</a>.</div>
 
-<div class='issue'> What's the difference with derivation? Is it necessary? This is <a href="http://www.w3.org/2011/prov/track/issues/61">ISSUE-61</a>.</div>
+<div class='pending'> What's the difference with derivation? Is it necessary? This is <a href="http://www.w3.org/2011/prov/track/issues/61">ISSUE-61</a>.</div>
 
 </section>