In IETF specifications, a Uniform Resource Characteristic (URC) is a string of characters representing the metadata of a Uniform Resource Identifier (URI), a string identifying a Web resource. URC metadata was envisioned to include sufficient information to support persistent identifiers, such as mapping a Uniform Resource Name (URN) to a current Uniform Resource Locator (URL). URCs were proposed as a specification in the mid-1990s, but were never adopted.
The use of a URC would allow the location of a Web resource to be obtained from its standard name, via the use of a resolving service. It was also to be possible to obtain a URC from a URN by the use of a resolving service. The design goals of URCs were that they should be simple to use, easy to extend, and compatible with a wide range of technological systems. The URC syntax was intended to be easily understood by both humans and software.