International Standard Recording Code
An International Standard Recording Code (ISRC) is used to uniquely identify musical recordings (audio and music video) similarly to how ISBN codes represent books. It is an official standard (ISO 3901). It is used in the tracking of sales and radio airplay. Different agencies in each country issue them; in the United States it is done by the RIAA (Record Industry Association of America).
An ISRC consists of 12 letters and numbers, usually shown with dashes for readability, like
JM-K40-14-00212. This is composed of a two-character country code (ISO 3166-1), a three character owner code, a two character year code, and a five character serial number (unique for a given owner and year).
These codes are for recordings; the underlying works should have International Standard Musical Work Codes. There may be a lot of different recordings of a given song, including covers, remixes, and alternate versions.