Identifying Metadata Elements with URIs: The CORES Resolution (D-Lib Magazine) by Tom Baker and Makx Dekkers.
A report on a meeting organised by CORES of several standards organisations that assign terms, with their aggrement - the CORES Resolution
(PDF ) to make URIs for their terms.
This is a key semantic web fundamental - from this the terms can be used in RDF and other semweb systems such as FOAF, OWL, TMs. The terms can also be described, related and mapped. I attended the original meeting to outline RDF and encourage them.