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 487 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 In practice, ISO 639-2 has largely been superseded by ISO 639-3 (2007), which includes codes for all the individual languages in ISO 639-2 plus many more.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.

B and T codes

While most languages are given one code by the standard, twenty of the languages described have two three-letter codes, a "bibliographic" code (ISO 639-2/B), which is derived from the English name for the language and was a necessary legacy feature, and a "terminological" code (ISO 639-2/T), which is derived from the native name for the language and resembles the language's two-letter code in ISO 639-1. There were originally 22 B codes; scc and scr are now deprecated. In general the T codes are favored; ISO 639-3 uses ISO 639-2/T.

Scopes and types

The codes in ISO 639-2 have a variety of "scopes of denotation", or types of meaning and use, some of which are described in more detail below. For a definition of macrolanguages and collective languages, see ISO 639-3/RA: Scope of denotation for language identifiers. Individual languages are further classified as to type:

Collections of languages

Some ISO 639-2 codes that are commonly used for languages do not precisely represent a particular language or some related languages (as the above macrolanguages). They are regarded as collective language codes and are excluded from ISO 639-3. The collective language codes in ISO 639-2 are listed below. Some language groups are noted to be remainder groups, that is excluding languages with their own codes, while other are not. Remainder groups are, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , and , while inclusive groups are , , , , , , , , , , , , , , , , , , , , , , , , , , and. The following code is identified as a collective code in ISO 639-2 but is (at present) missing from ISO 639-5: Codes registered for 639-2 that are listed as collective codes in ISO 639-5 (and collective codes by name in ISO 639-2): • afa Afro-Asiatic languages • alg Algonquian languages • apa Apache languages • art artificial languages • ath Athapascan languages • aus Australian languages • bad Banda languages • bai Bamileke languages • bat Baltic languages • ber Berber languages • bih Bihari languages • bnt Bantu languages • btk Batak languages • cai Central American Indian languages • cau Caucasian languages • cel Celtic languages • cmc Chamic languages • cpe creoles and pidgins, English-based • cpf creoles and pidgins, French-based • cpp creoles and pidgins, Portuguese-based • crp creoles and pidgins • cus Cushitic languages • day Land Dayak languages • dra Dravidian languages • fiu Finno-Ugrian languages • gem Germanic languages • ijo Ijo languages • inc Indic languages • ine Indo-European languages • ira Iranian languages • iro Iroquoian languages • kar Karen languages • khi Khoisan languages • kro Kru languages • map Austronesian languages • mkh Mon–Khmer languages • mno Manobo languages • mun Munda languages • myn Mayan languages • nah Nahuatl languages • nai North American Indian languages • nic Niger-Kordofanian languages • nub Nubian languages • oto Otomian languages • paa Papuan languages • phi Philippine languages • pra Prakrit languages • roa Romance languages • sai South American Indian languages • sal Salishan languages • sem Semitic languages • sgn sign languages • sio Siouan languages • sit Sino-Tibetan languages • sla Slavic languages • smi Sami languages • son Songhai languages • ssa Nilo-Saharan languages • tai Tai languages • tup Tupi languages • tut Altaic languages • wak Wakashan languages • wen Sorbian languages • ypk Yupik languages • znd Zande languages

Reserved for local use

The interval from qaa to qtz is "reserved for local use" and is not used in ISO 639-2 nor in ISO 639-3. These codes are typically used privately for languages not (yet) in either standard. Microsoft Windows uses the qps language code for pseudo-locales generated automatically from English strings, designed for testing software localization.

Special situations

There are four generic codes for special situations: These four codes are also used in ISO 639-3.