ISO 639-1

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.

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.

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

ISO 639, the original standard for language codes, was approved in 1967. 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. The original standard was redesignated as ISO 639-1 in 2002, in an updated version. 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".

The last two-letter code added was ht, representing Haitian Creole on February 26, 2003.