--- a/model/ProvenanceModel.html	Thu Aug 04 10:42:49 2011 +0100
+++ b/model/ProvenanceModel.html	Thu Aug 04 11:10:10 2011 +0100
@@ -356,9 +356,13 @@
 </p>
 
 
-<p>The language introduces a notion of "provenance container", which
-provides a default scope for assertions. The model may define additional scoping rules for assertions. 
-Identifiers can safely be used within that scope. Optionally,  identifiers can be exported so that they can be used outside their default scope. The language does not prescribe the mechanisms by which identifiers are generated.</p>
+<p>The data model includes a notion of "provenance container" that 
+ is a logical grouping of a set of assertion. It serves multiple purposes.
+First, it provides a way to attach various metadata to the set of assertions.
+Second, it provides a default scope for identifiers used in assertions.
+This means that identifiers are expected to be resolvable only within the scope of a container, rather than globally. Optionally,  identifiers can be exported so that they can be used outside their default scope.
+Finally,  the data model does not prescribe the mechanisms by which identifiers are generated.</p>
+
 
 
 <p>In this specification, when an assertion is defined to refer to another assertion about something, it does so by means of that thing's identifier.<p>