URN

A Uniform Resource Name (URN) are general URIs that refer to resources without disclosing any location or proof of existence.

Syntax

urn:nid:data

URNs use namespace identifiers (nid) that are unique and registered with the Internet Assigned Numbers Authority. The data is commonly unique information such as serial numbers.

Example

Libraries and booksellers may use the International Standard Book Number (ISBN) system to catalog and uniquely identify materials in their collection, like so:

urn:isbn:9781098110338