# ISO 639-5
**ISO 639-5** is the part of the [ISO 639](https://www.edgepedia.org/iso-639) language-code standard that assigns three-letter identifiers to language families and language groups, living and extinct. It was first published as ISO 639-5:2008 in May 2008[1](https://www.iso.org/standard/39536.html) and, since November 2023, has continued as Set 5 of the consolidated standard ISO 639:2023, which replaced the earlier separately published parts of the series[2](https://www.iso.org/standard/74575.html) • [3](https://www.iso.org/iso-639-language-code).
| Key fact | Detail |
|---|---|
| What it codes | Alpha-3 identifiers for living and extinct language families and groups[1](https://www.iso.org/standard/39536.html) |
| Original publication | ISO 639-5:2008, published May 2008, 23 pages, prepared by ISO/TC 37/SC 2[1](https://www.iso.org/standard/39536.html) • [4](https://www.iso.org/fr/standard/39536.html?browse=ics) |
| Current form | Set 5 of ISO 639:2023 (Edition 2, published 2023-11-08), which withdrew ISO 639-1 through 639-5 as separate standards[2](https://www.iso.org/standard/74575.html) |
| Registration authority | The Library of Congress is the Language Coding Agency (LCA) for Set 5[5](https://www.loc.gov/standards/iso639-5/) |
| Coverage | A larger set of language groups than ISO 639-2, including all groups covered by Set 2[3](https://www.iso.org/iso-639-language-code) |
| Example codes | afa Afro-Asiatic languages, alg Algonquian languages, zhx Chinese (family), euq Basque (family), jpx Japanese (family)[6](https://www.loc.gov/standards/iso639-5/en.php) |
| Stated purpose | To support the overall language coding of the ISO 639 series, not to provide a scientific classification of the world's languages[7](https://www.loc.gov/standards/iso639-5/langhome5.html) |
## Purpose and relation to other parts
ISO 639 as a whole provides codes for individual languages, language variants, and language groups[7](https://www.loc.gov/standards/iso639-5/langhome5.html). Part 2 (the alpha-3 code) already includes some language groups and families, but the list is not complete; those code elements exist so that the language of a document can be registered even when the specific individual language is not in the code table[5](https://www.loc.gov/standards/iso639-5/). Set 5 supplements this coding with a larger set of groups, living and extinct, that includes every group covered by Set 2[3](https://www.iso.org/iso-639-language-code).
The standard states explicitly what the code is not. Its depth and detail are intended to support language coding across the ISO 639 series rather than to provide a scientific classification of the languages of the world[7](https://www.loc.gov/standards/iso639-5/langhome5.html). A LoC note illustrates the difference: in many classifications "Caucasian" (covering both North Caucasian and South Caucasian) is not considered a language family at all, but rather two separate, unrelated families, yet the code entry cau exists as a coding convenience[6](https://www.loc.gov/standards/iso639-5/en.php).
## Content of the code list
Each entry carries an identifier, English and French names, and a hierarchy field indicating which other language families or groups the entry belongs to[8](https://www.loc.gov/standards/iso639-5/id.php). For example, [Algonquian languages](https://www.edgepedia.org/algonquian-languages) (alg) sit in the hierarchy nai : aql : alg, inside the North American Indian remainder group and the Algic family[8](https://www.loc.gov/standards/iso639-5/id.php), while Chinese (family) (zhx) sits inside Sino-Tibetan (sit)[9](https://www.loc.gov/standards/iso639-5/hier.php).
Entries are typed as either a **language group** or a **remainder group**. A remainder group, such as Afro-Asiatic languages (afa) or Artificial languages (art), covers the languages of the family not already assigned to more specific groups; a language group, such as Apache languages (apa) or Algonquian languages (alg), is an ordinary grouping[6](https://www.loc.gov/standards/iso639-5/en.php). Several family codes coexist with individual-language codes in the earlier parts, and the list notes this explicitly: Albanian languages (sqj) sit alongside Albanian as an individual language (sq / sqi / alb), Armenian (family) (hyx) alongside Armenian (hy / hye / arm), Basque (family) (euq) alongside Basque (eu / eus / baq), Chinese (family) (zhx) alongside Chinese (zh / zho / chi), Japanese (family) (jpx) alongside Japanese (ja / jpn), and Quechuan (family) (qwe) alongside Quechua (qu / que)[6](https://www.loc.gov/standards/iso639-5/en.php).
The code also includes groups such as sign languages (sgn), Creoles and pidgins (crp) with its English-, French-, and Portuguese-based subgroups, and broad geographic or genetic groupings from Indo-European (ine) to Trans-[New Guinea](https://www.edgepedia.org/new-guinea) (ngf)[6](https://www.loc.gov/standards/iso639-5/en.php).
## Maintenance and governance
Under ISO 639:2023 the language code comprises four sets of identifiers, and Set 5 is one of them[3](https://www.iso.org/iso-639-language-code). The ISO 639 Maintenance Agency (ISO 639/MA) maintains the standard, and maintenance of the sets is delegated to three Language Coding Agencies: Infoterm for Set 1, the Library of Congress for Sets 2 and 5, and SIL International for Set 3[3](https://www.iso.org/iso-639-language-code).
The Library of Congress, through its Network Development and MARC Standards Office, receives and reviews applications for new three-letter codes and for changes to existing ones, according to the criteria in ISO 639:2023. It maintains the list of registered codes, processes updates, and distributes them regularly to subscribers[5](https://www.loc.gov/standards/iso639-5/). The set is an open list that can be extended and refined; changes since the initial 2008 publication are listed in the ISO 639-5 Change Notice, which records decisions of the ISO 639 Joint Advisory Committee[7](https://www.loc.gov/standards/iso639-5/langhome5.html).
## Use in other standards
Internet language tags draw on the ISO 639 sets. RFC 5646 (BCP 47), which defines the language tags used across the web, allows a primary language subtag of three letters assigned by [ISO 639-2](https://www.edgepedia.org/iso-639-2), [ISO 639-3](https://www.edgepedia.org/iso-639-3), or ISO 639-5[10](https://datatracker.ietf.org/doc/rfc5646/). The standard is also reused directly in other vocabularies; for example, the US Common Education Data Standards imports its ISO 639-5 Language Family option set from the standard[11](https://ceds.ed.gov/cedselementdetails.aspx?termid=12619).
ISO permits free-of-charge use of its language codes, alongside its country and currency codes[3](https://www.iso.org/iso-639-language-code). Like the rest of ISO 639, the code excludes reconstructed languages and formal languages such as programming languages, and Set 5's own entries include a code for Artificial languages (art) as a grouping device rather than codes for individual constructed languages[2](https://www.iso.org/standard/74575.html) • [6](https://www.loc.gov/standards/iso639-5/en.php).
## Consolidation in 2023
Until 2023 the ISO 639 series was published as separate parts: [ISO 639-1](https://www.edgepedia.org/iso-639-1):2002, 639-2:1998, 639-3:2007, 639-4:2010, and 639-5:2008. All five were withdrawn when ISO 639:2023, Edition 2, was published on 8 November 2023 as a single standard, and the identifiers continue as Sets 1, 2, 3, and 5 of the consolidated code[2](https://www.iso.org/standard/74575.html).
## References
1. [ISO 639-5:2008 - Codes for the representation of names of languages — Part 5: Alpha-3 code for language families and groups, ISO](https://www.iso.org/standard/39536.html)
2. [ISO 639:2023 - Code for individual languages and language groups, ISO](https://www.iso.org/standard/74575.html)
3. [ISO 639 — Language code, ISO](https://www.iso.org/iso-639-language-code)
4. [ISO 639-5:2008 (French catalogue page), ISO](https://www.iso.org/fr/standard/39536.html?browse=ics)
5. [ISO 639-5 Language Coding Agency, Library of Congress](https://www.loc.gov/standards/iso639-5/)
6. [ISO 639-5 codes ordered by English name of language, Library of Congress](https://www.loc.gov/standards/iso639-5/en.php)
7. [Codes for the representation of names of languages, Part 5 home, Library of Congress](https://www.loc.gov/standards/iso639-5/langhome5.html)
8. [ISO 639-5 codes ordered by Identifier, Library of Congress](https://www.loc.gov/standards/iso639-5/id.php)
9. [ISO 639-5 codes ordered by Hierarchy, Library of Congress](https://www.loc.gov/standards/iso639-5/hier.php)
10. [RFC 5646: Tags for Identifying Languages, IETF](https://datatracker.ietf.org/doc/rfc5646/)
11. [CEDS ISO 639-5 Language Family, Common Education Data Standards](https://ceds.ed.gov/cedselementdetails.aspx?termid=12619)
---
*Topic: Encyclopedia › Society and history › Languages and linguistics › Languages and dialects › Language families and classification › Language codes and naming standards › ISO 639-5 and withdrawn parts*
*Initially written Sep 17, 2026 · Reviewed: Oct 25, 2026 · Edited: Oct 11, 2026; Oct 15, 2026; Oct 25, 2026 · Last review: Oct 25, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license