A Universal Resource Identifier (URI) is a member of this universal set of names in registered name spaces and addresses referring to registered protocols or name spaces. A Uniform Resource Locator (URL), defined elsewhere, is a form of URI which expresses an address which maps onto an access algorithm using network protocols. Existing URI schemes which correspond to the (still mutating) concept of IETF URLs are listed here. The Uniform Resource Name (URN) debate attempts to define a name space (and presumably resolution protocols) for persistent object names. This area is not addressed by this document, which is written in order to document existing practice and provide a reference point for URL and URN discussions.
This document is therefore to be issued under the "informational RFC" disclaimer .
The world-wide web protocols are discussed on the mailing list firstname.lastname@example.org and the newsgroup comp.infosystems.www is preferable for beginner's questions. The mailing list email@example.com has discussion related particularly to the URI issue. The author may be contacted as firstname.lastname@example.org.
This document is available in hypertext form at http://www.w3.org/hypertext/WWW/Addressing/URL/URI_Overview.html