Resource Description Framework (RDF)
As more and more content becomes available on the Internet, the need becomes keener for some standardized method for cataloguing and expressing information about a document's content. Basically, the RDF recommendation defines an XML vocabulary for making informative statements about things. For instance, expressing the idea that "W. Scott Means is the author of Strategic XML" could be encoded in RDF like this:
<?xml version="1.0"?> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:sxml="http://namespaces.strategicxml.com/example/bookinfo"> <rdf:Description about="Strategic XML"> <sxml:Author>W. Scott Means</sxml:Author> </rdf:Description> </rdf:RDF>
As with XLink, the acceptance of RDF is considered to be an important part of the development of the semantic web. If more document authors take steps to provide meta-information about the information they publish, search engines will be able to provide higher-quality content to end users.