--- a/model/prov-constraints.html	Thu Jul 19 12:24:53 2012 -0400
+++ b/model/prov-constraints.html	Thu Jul 19 18:41:23 2012 +0200
@@ -2737,7 +2737,10 @@
 <p> <span class="conditional">IF</span> <span  class="name">entity(id,_attrs1)</span> and <span
    class="name">activity(id,_t1,_t2,_attrs2)</span> <span class="conditional">THEN</span> <span class="conditional">INVALID</span>.</p>
   </div>
-
+	<div class="remark">
+	Note that there is no disjointness between entities and agents. This is because one might want to make statements about the provenance of an agent, by making it an entity. 
+	Thus, one MAY assert both <span class="name">entity(a1)</span> and <span class="name">agent(a1)</span> in a valid PROV instance. However, it is recommended that users SHOULD refrain from using the same identifier for an entity and an agent unless they refer to the same thing.
+  </div>
 
 
 </section> <!--impossibility-constraints -->