https://open-services.net/bin/view/Main/OSLCCoreSpecQuery has the following text for an example:

"Property values will often refer to or be other resources (in RDF/XML the rdf:resource attribute is used to identify the resource). Suppose bugs are linked to testcases using a property name qm:testcase where the prefix qm: stands for the URI http://qm.example.com/ns. The following query finds all bugs that are linked to testcase http://example.com/tests/31459: "

I don't think it's appropriate for the spec to define an arcane referencce to rdf:resource that is solely a feature of RDF/XML serialization.