Re: comments on concepts doc

gk:
> (a) there may be alternative serialization forms
> (b) RDF/XML is the (only) one that is standardized by this family of
> specifications

There is a need to counterbalance a view that N-triples is a normative
serialization. N-Triples get used by: RDF test cases; RDF Syntax; OWL test
case and OWL abstract Syntax (sort of).

Given that RDF/XML is disgusting and N-triples (and N3) aren't if we don't
emphasis that N-triples is not a standard then there is a danger of
misunderstanding.

Whether this belongs here or not is another issue.

Some of my comments on the syntax doc had the intent of emphasising the lack
of normativity of N-triple.

Jeremy