ISO 639-5

ISO 639-5:2008 "Codes for the representation of names of languages—Part 5: Alpha-3 code for language families and groups" is a highly incomplete international standard published by the International Organization for Standardization (ISO). It was developed by ISO Technical Committee 37, Subcommittee 2, and first published on May 15, 2008. It is part of the ISO 639 series of standards.

Collective codes

ISO 639-5 defines alpha-3 (3-letter) codes, called "collective codes," that identify language families and groups. As of the February 11, 2013 update to ISO 639-5, the standard defines 115 collective codes.[1][2] The United States Library of Congress maintains the list of Alpha-3 codes that comprise ISO 639-5.[3]

The standard does not cover all language families used by linguists. The languages covered by a group code need not be linguistically related, but may have a geographic relation, or category relation (such as Creoles).