[mdr-users] Clustering the UML for Traceability

Hi,
I want to use a minimal metamodel for storing traceability
information.  Right now, I only use two MOF classes: Trace and Node. 
The node class has an attribute "role" of type String and an attribute
"content" whose type is the superclass of the metamodel of the
language for modeling applications.  In the case of UML, this is
ModelElement.

The UML models need to be stored in plain UML-XMI.  Therefore, I think
my "Tracing" metamodel needs to cluster the UML metamodel.  Hence my
question: how do I represent the UML 1.4 metamodel in the UML profile
for MOF?  On the NetBeans MM site, I could not find the UML-XMI
defining the UML metamodel but only the MOF-XMI.  Then again, I don't
know if the UML profile for MOF actually requires the UML definition
of all clustered metamodels... perhaps I can use an empty package with
the proper tags on it as a stub for "the" actual UML metapackage?

Are there any examples of clustering the UML?  If not, could you
please help me creating such an example?

Thanks a lot in advance,
-- 
Pieter Van Gorp
       Teaching and Research Assistant
       FOrmal Techniques in Software engineering (FOTS)
       University of Antwerp
       Middelheimlaan 1
       2020 Antwerpen - Belgium
       Office: G.304
       Phone: +32 3 265 38 71
       Fax: +32 3 265 37 77
       http://www.fots.ua.ac.be/~pvgorp/research/
       http://motmot.sourceforge.net/