scope:

This standard provides specifications for identifying an eligible security, financial instrument, or other investment media referred to hereinafter as an issue. It uniquely identifies the issuer, and with a few exceptions for high-volume fixed income programs, the issue as well. It shall serve as the common denominator in communications among users for completion of transactions and exchange of information. It specifies both the configuration of the number and the meaning attached to each portion. (See Informative Annex C 8.2 for more information)