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I said:

> Based on my reading of sections 2.3.1 and 2.3.2 of RDF Schema, I think the
> first example above says:
>
> "the class dcq:LCSH is an _instance_ of the class dcq:SubjectScheme"
>
> This seems a reasonable statement.
>
> The second says
>
> "the class dcq:LCSH is a _subset_ of the class dcq:SubjectScheme,
> and therefore:
> an instance of class dcq:LCSH is an instance of class dcq:Subject Scheme"
>
> The latter statement does _not_ seem right to me (A LCSH subject heading
is
> not a subject scheme).
>
> So, to cut a long story short, I'm increasingly unsure about whether
> rdf:subClassOf is the appropriate way to describe the relationship between
> dcq:LCSH and dcq:SubjectScheme. I think maybe the relationship should be
one
> of rdf:type, as in the DCQ in RDF document. But I think I need someone
much
> more versed in RDF/RDFS to make that judgement!

Thinking about this a bit more, would it be more appropriate to say
something like this?

<rdfs:Class rdf:about = "&dcqns;SubjectTerm">
  <rdfs:label>Subject Terms</rdfs:label>
  <rdfs:comment>The set of terms which serve as values for
subject</rdfs:comment>
  <rdfs:isDefinedBy rdf:resource = "&dcqns;" />
</rdfs:Class>

<rdfs:Class rdf:about = "&dcqns;LCSH">
  <rdfs:label>LCSH</rdfs:label>
  <rdfs:comment>Library of Congress Subject Headings</rdfs:comment>
  <rdfs:subClassOf rdf:resource = "&dcqns;SubjectTerm" />
  <rdfs:isDefinedBy rdf:resource = "&dcqns;" />
</rdfs:Class>

This then says

"the class dcq:LCSH is a _subset_ of the class dcq:SubjectTerm,
and therefore:
an instance of class dcq:LCSH is an instance of class dcq:SubjectTerm"

i.e. any LCSH heading is a subject _term_ (not a subject _scheme_)

which seems correct.

Pete