The International Standard Musical Work Code (ISWC) is an ISO standard similar to ISBNs for identifying musical works / compositions.
According to the Wikipedia article about ISWC, to register an ISWC, the following minimal metadata must be supplied:
- names of all composers, arrangers and authors, with their role in the piece (identified by role code) and their CAE/IPI number
- work classification code (CIS (?))
- identification of other works it is a derivative of