Source : Free On-Line Dictionary of Computing

Uniform Resource Name
     
         (URN) 1. Any {URI} which is not a {URL}.
     
        2. A particular scheme which is currently (1991-4) under
        development by the {IETF}, which should provide for the
        resolution using {Internet} {protocol}s of names which have a
        greater persistence than that currently associated with
        Internet {host} names or organisations (as used in {URL}s).
        Uniform Resource Names will be URI schemes that improve on
        URLs in reliability over time, including authenticity,
        replication, and high availability.
     
        When defined, a URN in sense 1 will be an example of a URN in
        sense 2.
     
        {(http://www.w3.org/pub/WWW/Addressing/Addressing.html)}.
     
        (1995-10-27)