[Proposal][SKOS-Core] Some DC extensions around dc:subject

From sources outside this mailing list I've received requirements for: 

(a) An inverse of dc:subject

(b) A dc:subject style equivalent to foaf:primaryTopic

... So I propose to add some properties to SKOS Core, as placeholders in the
interim before (hopefully) such props end up in the DC or DCTerms namespace.

Add to SKOS Core ...

skos:isSubjectOf		a	rdf:Property;
	owl:inverseOf	dc:subject;
	rdfs:range		rdf:Resource;
	vs:term_status	'unstable'.

skos:primarySubject	a	rdf:Property;
	rdfs:subPropertyOf	dc:subject;
	vs:term_status	'unstable'.

skos:isPrimarySubjectOf	a	rdf:Property;
	rdfs:subPropertyOf	skos:isSubjectOf;
	owl:inverseOf	skos:primarySubject;
	vs:term_status	'unstable'.

Comments?

Al.

---
Alistair Miles
Research Associate
CCLRC - Rutherford Appleton Laboratory
Building R1 Room 1.60
Fermi Avenue
Chilton
Didcot
Oxfordshire OX11 0QX
United Kingdom
Email:        a.j.miles@rl.ac.uk
Tel: +44 (0)1235 445440