The Metadata Registry provides services to developers and consumers of controlled vocabularies and is one of the first production deployments of the RDF-based Semantic Web Community's Simple Knowledge Organization System (SKOS)
The Publishing Requirements for Industry Standard Metadata (PRISM) specification defines a standard for interoperable content description, interchange, and reuse in both traditional and electronic publishing contexts. PRISM recommends the use of certain existing standards, such as XML, RDF, the Dublin Core, and various ISO specifications for locations, languages, and date/time formats. Beyond those recommendations, it defines a small number of XML namespaces and controlled vocabularies of values, in order to meet the goals listed above.
In an attempt to summarize the relationship among various metadata formats and how they relate to building Internet systems I wrote a glossary. I then ordered and tied the terms together with a bit of narrative to explain the relationships among the terms