BS ISO 639-6:2009

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Alpha-4 language identifier
5 Language and language variants
6 Structure
7 Extension coding and register
8 Administration of code assignments
Annex A (informative) - Example data
Annex B (normative) - Operation of the Registration Authority
        (ISO 639-6/RA) and the Registration Authorities
        Advisory Committee for ISO 639 (ISO 639/RA-JAC)
Bibliography

Describes a method for establishing four-letter language identifiers (alpha-4) and language reference names for language variants and a hierarchical framework for relating them to languages, language families and language groups.

This part of ISO639 specifies a method for establishing four-letter language identifiers (alpha-4) and language reference names for language variants and a hierarchical framework for relating them to languages, language families and language groups. The alpha-4 language identifiers have been developed for use in a wide range of applications, especially in computer systems, where there is a potential need to cover the entire range of languages, language families and language groups as well as language variants within each identified language. Alpha-4 language identifiers can support the quantity of known language variants and accommodate any future expansion.

This part of ISO639 provides a hierarchical framework, which facilitates backward compatibility with other ISO639 codes, based on linguistic and/or geolinguistic relationships, within which a comprehensive enumeration of language variants is possible, including living, extinct, ancient and constructed languages, whether major or minor. As a result, this part of ISO639 caters for a very large number of languages and their variants. This part of ISO639 is not applicable to the registrations for languages designed exclusively for machine use, such as computer-programming languages and reconstructed languages.