ISO 639-3

ISO 639-3 is part of the ISO 639 family of standards designed to assign codes to languages. It uses three-letter codes to identify each language; for example, `som` represents Somali. The purpose is to refer to languages consistently in data storage, libraries, and computer applications.

What distinguishes ISO 639-3 from earlier parts of the standard is its scope. Where ISO 639-1 (two letters) and ISO 639-2 (three letters) cover only a small number of major languages or language groups, ISO 639-3 attempts to code all known human languages—those spoken, extinct, and constructed languages as well.

Administration and procedures

ISO has designated a subsidiary body to manage the register (the registration authority), which is SIL International. That body accepts proposals—such as the creation of a new code, the merger of two languages, or the division of one—and then releases an annual update to the list containing approved changes.

Categories and types of codes

Codes are organized by how they are classified: those representing individual languages currently spoken, those representing extinct languages, and those representing constructed languages. There are also special codes for situations such as when a language cannot be identified or when an appropriate language label is not available.

Use

ISO 639-3 codes underpin language identification in web and software systems, and are used in linguistics research, library cataloging, and translation projects. Projects such as Wikidata and Wikipedia use these codes to link languages consistently in their records.