What is ISIN?
A security is identified by its ISIN (International Securities Identification Number).
ISO 6166 specifies its structure.
The ISIN code is a 12-character alphanumeric identifier that allows for universal identification of a security during trading and settlement by normalizing the allocated National Number, if one exists.
ISINs were originally used in 1981, but it wasn't until 1989 that the G30 countries urged their use that they gained widespread popularity.
ISO recognized the ISIN with the ISO 6166 standard a year later.