ISO 639-1
ISO 639-1:2002, Codes for the representation of names of languages—Part 1: Alpha-2 code, is the first part of the ISO 639 series of international standards for language codes. Part 1 covers the registration of "set 1" two-letter codes.[1] There are 183 two-letter codes registered as of June 2021. The registered codes cover the world's major languages.
Infoterm (International Information Centre for Terminology) is the registration authority for ISO 639-1 codes.
These codes are a useful international and formal shorthand for indicating languages.
| Code | ISO 639-1 language name | Endonym |
|---|---|---|
| English | ||
en |
English | English |
es |
Spanish | español |
pt |
Portuguese | português |
zh |
Chinese | 中文, Zhōngwén |
ISO 639-1 is more restrictive than other ISO 639 parts, such as ISO 639-2 and ISO 639-3, which cover a wider range of languages and variations.[2]
Many multilingual websites, including Wikipedia, use these codes to prefix URLs of localised versions: for example, ja.wikipedia.org is the Japanese version of Wikipedia.
History
[edit]ISO 639, the original standard for language codes, was approved in 1967.[3] It was designed to represent major and primary national languages with well-established terminologies and lexicography.
In 1998 the standard was extended with an additional part, ISO 639-2, providing three-letter codes for a much wider range of languages.[4] The original standard was redesignated as ISO 639-1 in 2002, in an updated version.[1] Eventually five parts were issued, each being maintained as a separate standard.
In 2023, the different parts were combined into a unified standard, with the different code lists from each part now designated "sets".[5][6]
The last two-letter code added was ht, representing Haitian Creole on February 26, 2003.[7]
Updates
[edit]New ISO 639-1 codes are not added if an ISO 639-2 "set 2" three-letter code exists, so systems that use ISO 639-1 and 639-2 codes, with 639-1 codes preferred, do not have to change existing codes.[8]
If an ISO 639-2 code that covers a group of languages is used, it might be overridden for some specific languages by a new ISO 639-1 code.
Part 3 (2007) of the standard, ISO 639-3, aiming to cover all known natural languages, largely supersedes the ISO 639-2 three-letter code standard.
There is no specification on treatment of macrolanguages, which are covered by ISO 639-3.
IETF language tags
[edit]The use of ISO 639 language codes was encouraged by the introduction of IETF language tags via RFC 1766 in March 1995.[9] The current version of the specification is RFC 5646 from September 2009.[10]
See also
[edit]- Lists of ISO 639 codes
- ISO 3166-1 alpha-2, a different set of two-letter codes used for countries
References
[edit]- ^ a b "ISO 639-1:2002". ISO. July 2002. Retrieved 5 October 2025.
- ^ "Frequently Asked Questions (FAQ) - Codes for the representation of names of languages (Library of Congress)". Language Coding Agency. Library of Congress. Retrieved 5 October 2025.
- ^ "ISO/R 639:1967". International Organization for Standardization. 1988-03-01. Retrieved 2012-08-05.
- ^ ISO 639-2:1998 – Codes for the representation of names of languages – Part 2: Alpha-3 code.
- ^ "ISO 639 – Language code". International Organization for Standardization.
- ^ ISO 639:2023 – Code for individual languages and language groups.
- ^ "ISO 639-1 Languages: Haitian". Library of Congress.
- ^ ISO 639 Joint Advisory Committee - Working principles for ISO 639 maintenance
- ^ H. Alvestrand (March 1995). Tags for the Identification of Languages. Network Working Group. doi:10.17487/RFC1766. RFC 1766. Obsolete. Obsoleted by RFC 3066 and 3282.
- ^ Phillips, A.; Davis, M., eds. (September 2009). Tags for Identifying Languages. IETF Network Working Group. doi:10.17487/RFC5646. BCP 47. RFC 5646. Best Current Practice 47. Obsoletes RFC 4646.
