International Standard Musical Work Code (ISWC)

The ISWC (International Standard Musical Work Code) is a unique, permanent and internationally recognized reference number for the identification of musical works.

The ISWC is part of the CIS plan (Common Information System) which CISAC, the confederation of societies of authors, has developed in order to respond to the needs for information in the digital age.

The ISWC has been approved by ISO (International Organization for Standardisation). There is an official document that defines how the ISWC should be structured, as well as the rules governing its issuance and application.

An ISWC begins with the letter “T”, followed by a nine-digit unique number (from 00000001 to 999999999), and an additional check digit at the end. (Written Format: T-345246800-1).

An ISWC is only allocated by a qualified numbering agency when all the creators have been uniquely identified.

What is the descriptive metadata for an ISWC?
The descriptive metadata for an ISWC includes:

the title of the work
all composers, authors and arrangers of the work identified by their IPI numbers and role codes
the work classification code (from the CIS standards list)
in the case of ‘versions’, for example arrangements, identification of the work from which the version was made.

http://www.iswc.org