Library of Congress >> Standards


Criteria for ISO 639-2

This document was revised on 22 Sept. 2006 as approved by the ISO 639 Joint Advisory Committee on 10 June 2006. This replaces the published text in ISO 639-2, sections 4.1.1, 4.1.3, and A.2.1.

ISO 639-2 defines a proper subset of the totality of alpha-3 language identifiers in all parts of ISO 639. The primary applications for which ISO 639-2 is intended include libraries, archives and other documentation applications. Thus, the general criterion for inclusion of a language in ISO 639-2 is that there is a significant body of literature in the language or describing the language. In order to establish this, the following objective and subjective metrics will be applied.

  • Number of documents.
    The request for a new language identifier shall include evidence that one agency holds 50 different documents in the language or that five agencies hold a total of 50 different documents among them in the language. Documents include all forms of material and are not limited to text. This is a necessary requirement, but not sufficient in and of itself. In addition the following requirements will be considered.
  • Size and variety of literature.
    The size and variety of the literature in the language, be it written or oral, will be considered and should be documented in the proposal. The documentation may be in the form of reference to library holdings or
    bibliographies or more general statements quantifying the literature and its variation.
  • National or regional support
    The proposal should preferably be explicitly supported by a national or regional language authority or standardizing body. If such support for some reason is unobtainable, a recommendation from another authority or language organization will be taken into account.
  • Formal or official status
    If the language in question has some sort of “official” status, documentation of this status will greatly support the proposal. The assignment of formal status to languages is in no way consistently practiced throughout the world, and the lack of such status is not a negative argument if other requirements are met.
  • Formal education
    If the language is used as a means of instruction in formal education on any level, documentation of this use will support the proposal. Teaching of the language is also relevant, in particular if the teaching is extensive.

    Other considerations
  • Collective codes.
    If the criteria above are not met the language may be assigned a new or existing collective language code. The words languages or other as part of a language name indicates that a language code is a collective one.
  • Scripts.
    A single language code is normally provided for a language even though the language is written in more than one script. ISO 15924 Codes for the representation of names of scripts provides coding for scripts.
  • Dialects.
    A dialect of a language is usually represented by the same language code as that used for the language. If there are multiple names for the same language each will be included with a single code. If the language is assigned to a collective language code, the dialect is assigned to the same collective language code. The difference between dialects and languages will be decided on a case-by-case basis.
  • Orthography.
    A language using more than one orthography is not given multiple language codes.

Individual languages that do not meet the criteria enumerated above may be candidates for inclusion in ISO 639-3 (Codes for the representation of names of languages - Part 3: Alpha-3 code for comprehensive coverage of languages). As of September 2006, ISO 639-3 is in final draft stage and is expected to be published as an International Standard soon.

Comments on this document: [email protected]

Library of Congress >> Standards

Legal | External Link Disclaimer

Contact Us
October 18, 2010