ISO 639

ISO 639 is a set of standards by the International Organization for Standardization that is concerned with representation of names for language and language groups.

It was also the name of the original standard, approved in 1967 (as ISO 639/R) and withdrawn in 2002. The ISO 639 set consists of five parts.

The current and historical parts of the standard

Each part of the standard is maintained by a maintenance agency, which adds codes and changes the status of codes when needed. ISO 639-6 was withdrawn in 2014.

Characteristics of individual codes

Scopes:

Types (for individual languages):

ISO 639-2

ISO 639-2:1998, Codes for the representation of names of languages — Part 2: Alpha-3 code, is the second part of the ISO 639 standard, which lists codes for the representation of the names of languages. The three-letter codes given for each language in this part of the standard are referred to as "Alpha-3" codes. There are 464 entries in the list of ISO 639-2 codes.

The US Library of Congress is the registration authority for ISO 639-2 (referred to as ISO 639-2/RA). As registration authority, the LOC receives and reviews proposed changes; they also have representation on the ISO 639-RA Joint Advisory Committee responsible for maintaining the ISO 639 code tables.

History and relationship to other ISO 639 standards

Work was begun on the ISO 639-2 standard in 1989, because the ISO 639-1 standard, which uses only two-letter codes for languages, is not able to accommodate a sufficient number of languages. The ISO 639-2 standard was first released in 1998.

In practice, ISO 639-2 has largely been superseded by ISO 639-3 (2007), which includes codes for all the individual languages in ISO 639-2 plus many more. It also includes the special and reserved codes, and is designed not to conflict with ISO 639-2. ISO 639-3, however, does not include any of the collective languages in ISO 639-2; most of these are included in ISO 639-5.