--- a/model/prov-dm.html	Thu Oct 25 15:39:24 2012 -0600
+++ b/model/prov-dm.html	Fri Oct 26 10:01:16 2012 +0100
@@ -2171,7 +2171,7 @@
 
 
 <p>According to <a href="#section-prov-overview">Section 2</a>, for an entity to be transformed from, created from, or resulting from an update to another, there must be some
-underpinning activities performing the necessary actions resulting in such a derivation.  
+underpinning activity or activities performing the necessary action(s) resulting in such a derivation.  
 A derivation can be described at various levels of precision. In its simplest form, derivation relates two entities. Optionally, attributes can be added to represent further information about the derivation.  If the derivation is the result of a single known activity, then this activity can also be optionally expressed. To provide a completely accurate description of the derivation, the generation and usage of the generated and used entities, respectively, can be provided, so as to make the derivation path, through usage, activity, and generation, explicit.  Optional information such as activity, generation, and usage can be linked to derivations to aid analysis of provenance and to facilitate provenance-based reproducibility. </p>
 
 
@@ -3889,6 +3889,7 @@
 <li> <a href="http://www.w3.org/2011/prov/track/issues/499">ISSUE-499</a>: Made explicit that generation/usage/invalidation/start/end are implicit.
 <li> <a href="http://www.w3.org/2011/prov/track/issues/449">ISSUE-449</a>: Clarified definition of prov:value attribute and added an example.
 <li> <a href="http://www.w3.org/2011/prov/track/issues/495">ISSUE-495</a>: added paragraph about 'relations opening up'. Clarified the role of '-' in example. Fixed dates in biblio. Fixed space issue in prov-n examples
+<li> <a href="http://www.w3.org/2011/prov/track/issues/516">ISSUE-516</a>: Stating that there moust be some underpinning activity or activities for a derivation, instead of just activities.
 </ul>
 
 </section>