Pasto language

Pasto is a purported Barbacoan language that was spoken by Indigenous people of Pasto, Colombia and Carchi Province, Ecuador. It is now extinct.

ISO issue
Prior to its retirement, the ISO name of the ISO code  was Barbacoas, the name of an extinct people who gave their name to the Barbacoan language family of which Pasto is a member, as well as to the Colombian town of Barbacoas. However, nothing is known of their language, one of several also known as Colima, and it can only be assumed to be part of the Barbacoan family. Such unattested, long-extinct languages are not normally assigned ISO codes. MultiTree conflates Barbacoas with neighboring Pasto, which is attested sufficiently for classification and assignment of an ISO code. This does not, however, mean that the retired ISO code  can be properly used for the Pasto language.

Glottolog distinguishes unclassifiable  'Pasto' from unattested   'Barbacoas'.