Hi all, The XML syntax currently uses a "Relation" element to describe relations between different elements in a description. The type of the relation is then given using the "type" attribute of that element. In RDF relations are a much more natural element of the model. Using the same kind of "type" attribute to NML "Relations" would make for an awkward description where complete RDF triples would have to be annotated to describe the type of a relation. I would propose that we define a "Relation" element as the top relation in the NML RDF schema, and then make the typed NML relations sub-properties of that. For example: <nml:Node id="urn:ogf:network:internet2.edu:2011:rtr.atla.net"> <nml:Relation type="hasPort"> <nml:Port idRef="urn:ogf:network:internet2.edu:2011:rtr.atla.net:ge-6-0-0_in" /> </nml:Relation> </nml:Node> Would be translated to: nml:hasPort rdfs:subPropertyOf nml:Relation . <urn:ogf:network:internet2.edu:2011:rtr.atal.net> a nml:Node; nml:hasPort <urn:ogf:network:internet2.edu:2011:rtr.atla.net:ge-6-0-0_in> . <urn:ogf:network:internet2.edu:2011:rtr.atla.net:ge-6-0-0_in> a nml:Port . This does mean that we have to explicitly define the relation types in the schemas though. Jeroen.