must properties be of the form foo#bar

Am I correct in thinking that properties (by which I mean the second part of
an RDF triple) *must* be of the form foo#bar and hence serialized:

	[ inside Description or typed node ]
    <f:bar xmlns:f="foo#">...</f:bar>

	or

	[ as attributes on Description or typed node ]
	... f:bar="..." xmlns:f="foo#"

If not, I can't see how they can be serialized. How would
('foo','bar','baz') or ('foo','http://www.bar.com/','baz') be serialized?

Is this true? 

James Tauber