The Resource Description Framework RDF allows you to describe web documents and resources from the real world—people, organisations, things—in a computer-processable way. Publishing such descriptions on the web creates the semantic web. URIs are very important as the link between RDF and the web. This article presents guidelines for their effective use.
The idea of markup languages was apparently first publicly presented by the engineer William W. Tunnicliffe (1922-1996) from Washington, D.C. In September of 1967, during a meeting at the Canadian Government Printing Office, Tunnicliffe gave a presentation on the separation of information content of documents from their format.