IETF language tag

An IETF BCP 47 language tag is a standardized code that is used to identify human languages on the Internet.[1] The tag structure has been standardized by the Internet Engineering Task Force (IETF) [1] in Best Current Practice (BCP) 47;[1] the subtags are maintained by the IANA Language Subtag Registry.[2][3][4]

To distinguish language variants for countries, regions, or writing systems (scripts), IETF language tags combine subtags from other standards such as ISO 639, ISO 15924, ISO 3166-1 and UN M.49. For example, the tag en stands for English; es-419 for Latin American Spanish; rm-sursilv for Romansh Sursilvan; sr-Cyrl for Serbian written in Cyrillic script; nan-Hant-TW for Min Nan Chinese using traditional Han characters, as spoken in Taiwan; and gsw-u-sd-chzh for Zürich German.

It is used by computing standards such as HTTP,[5] HTML,[6] XML[7] and PNG.[8]󠀁

  1. ^ a b c Phillips, Addison; Davis, Mark (September 2009). "Information on BCP 47 » RFC Editor".
  2. ^ "Language Subtag Registry". iana.org. Internet Assigned Numbers Authority. Retrieved 2018-12-05.
  3. ^ "Language Tag Extensions Registry". iana.org. Internet Assigned Numbers Authority. Retrieved 2018-12-06.
  4. ^ "IANA — Protocol Registries". iana.org. Retrieved 28 July 2015.
  5. ^ Fielding, Roy T.; Reschke, Julian F., eds. (June 2014). "Language Tags". Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content. sec. 3.1.3.1. doi:10.17487/RFC7231. RFC 7231.
  6. ^ "Language information and text direction". w3.org. Retrieved 28 July 2015.
  7. ^ "Extensible Markup Language (XML) 1.0 (Fifth Edition)". w3.org. Retrieved 28 July 2015.
  8. ^ "Portable Network Graphics (PNG) Specification (Second Edition)". w3.org. Retrieved 28 July 2015.