This document defines the syntax used by the World-Wide Web initiative to encode the names and addresses of objects on the Internet. The web is considered to include objects accessed using an extendable number of protocols, existing, invented for the web itself, or to be invented in the future. Access instructions for an individual object under a given protocol are encoded into forms of address string. Other protocols allow the use of object names of various forms. In order to abstract the idea of a generic object, the web needs the concepts of the universal set of objects, and of the universal set of names or addresses of objects.
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.
The world-wide web protocols are discussed on the mailing list www- email@example.com and the newsgroup comp.infosystems.www is preferable for beginner's questions. The mailing list uri- firstname.lastname@example.org has discussion related particularly to the URI issue. The author may be contacted as email@example.com.
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