International Standard Musical Work Code (ISWC) is a unique identifier for musical works, similar to ISBN for books. Starting with a T followed by 10 digits, it is typically formatted as T-000.000.000-0. ISWC codes help identify a musical composition and its owners, making music licensing and royalty collection much easier. These codes are typically provided by a publisher or writer's PRO.
The International Standard Recording Code (ISRC) is an international standard code for uniquely identifying sound recordings and music video recordings. ISRC codes help track the use of sound recordings and compositions on digital services, and is typically provided by an ISRC manager, record label, or your digital distributor.