RDF subjects and objects in the content of ODF

[Svante Schubert <Svante.Schubert@Sun.COM>]

It seems the Use Case #3 of Bernd's list needs our attention.
In Example #3 Bernd expresses a Use Case solution, where both RDF 
subject and object are contained inside the content.xml.

This seems a valid Use Case, but the RDF used seems expressing something 
different.
Let us take a look at the RDF noted in N3:

@prefix ex: <http://wiki.oasis-open.org/office/ExampleDocument#> .
**"offering the proposals" ex:deadline "end of february".

This statement has to be modified as literals are only able to be a 
subject in RDF [1].
The minimum modification would be result into something like:

@prefix ex: <http://wiki.oasis-open.org/office/ExampleDocument#> .
ex:task   ex:description "offering the proposals" .
ex:task   ex:deadline "end of february" .

But by this, we suddenly have a relation of two RDF objects and not of a 
RDF subject and object in the text.

The question is how does a Use Case look like, when the subject is in 
the content?
Most likely when someone likes to add metadata to a ODF element, like a 
table or a graphic.
What does the group think on this?

Regards,
Svante

[1] "A literal may be the object of an RDF statement, but not the 
subject or the predicate.", from 
http://www.w3.org/TR/rdf-concepts/#section-Literals