ISO 639-1:2002,Codes for the representation of names of languages—Part 1: Alpha-2 code, is the first part of theISO 639 series ofinternational standards forlanguage 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.
Some languages do not have the ISO 639-1 codes because the standard was initially designed to represent major and primary national languages with well-established terminologies and lexicography. The ISO 639-1 is more restrictive than other ISO 639 standards, such as ISO 639-2 as well as ISO 639-3, which cover a wider range of languages and variations.[2]
These codes are a useful international and formal shorthand for indicating languages.
Many multilingual web sites—such asWikipedia—use these codes to prefix URLs of specific language versions of their web sites: for example, en.Wikipedia.org is the English version of Wikipedia. See alsoIETF language tag. (Two-letter country-specifictop-level-domain code suffixes are often different from these language-tag prefixes).
ISO 639, the original standard for language codes, was approved in 1967.[3] It was split into parts, and in 2002 ISO 639-1 became the new revision of the original standard.[1] The last code added washt, representingHaitian Creole on February 26, 2003.[4] The use of the standard was encouraged byIETF language tags, introduced in RFC 1766 in March 1995, and continued by RFC 3066 from January 2001 and RFC 4646 from September 2006. The current version is639-1 RFC 5646 from September 2009.Infoterm (International Information Center for Terminology) is the registration authority for ISO 639-1 codes.
New ISO 639-1 codes are not added if anISO 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.[5]
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 knownnatural languages, largely supersedes theISO 639-2 three-letter code standard.
ISO 639-1 codes added after RFC publication in January 2001
