The ISRC (International Standard Recording Code) is a 12-character alphanumeric code used to identify a unique sound recording. One song can have multiple ISRCs if more than one recording of the song has been released - like live, acoustic, or cover versions. Publishers, collection societies, and music services use ISRCs to match specific recordings to the underlying compositions. ISRCs are typically assigned by labels or distributors. An ISRC looks like this: USS1Z9900001.