Dublin Core

" Effective use of metadata requires three things: a set of commonly-understood terms to describe the content of information resources (semantics); a standard grammar for connecting those terms in meaningful metadata sentences; and a framework that allows us to exchange and recombine those metadata sentences across different applications and subjects. … The Dublin Core Metadata Element Set (DCMES) can be viewed as the common semantic building block of Web metadata. Its 15 broad categories (elements) are useful for creating simple, easy-to-understand descriptions for most information resources."

• Terms: http://dublincore.org/documents/dcmi-terms/
• http://dublincore.org/
• XMl.com Dublin Core Introduction