ISO 639 is a set of standards by the International Organization for Standardization that is concerned with representation of names for language and language groups.
Contents
- Current and historical parts of the standard
- Characteristics of individual codes
- Relations between the parts
- Alpha 2 code space
- Alpha 3 code space
- Alpha 4 code space
- References
It was also the name of the original standard, approved in 1967 (as ISO 639/R) and withdrawn in 2002. The ISO 639 set consists of five parts.
Current and historical parts of the standard
Each part of the standard is maintained by a maintenance agency, which adds codes and changes the status of codes when needed. ISO 639-6 was withdrawn in 2014.
Characteristics of individual codes
Scopes:
Types (for individual languages):
Bibliographic and terminology codes
Relations between the parts
The different parts of ISO 639 are designed to work together, in such a way that no code means one thing in one part and something else in another. However, not all languages are in all parts, and there is a variety of different ways that specific languages and other elements are treated in the different parts. This depends, for example, whether a language is listed in parts 1 or 2, whether it has separate B/T codes in part 2, or is classified as a macrolanguage in part 3, and so forth.
These various treatments are detailed in the following chart. The first four columns contain codes for a representative language that exemplifies a specific type of relation between the parts of ISO 639. The last column provides an explanation of the relationship, and the "#" column indicates the number of elements that have that type of relationship. For example, there are four elements that have a code in part 1, have a B/T code, and are classified as macrolanguages in part 3. One representative of these four elements is "Persian" [fas].
These differences are due to the following factors:
de) has two codes in Part 2: ger (B code) and deu (T code), whereas there is only one code in Part 2, eng, for the English language.qaa through qtz are reserved for local use.mis for languages that have no code yet assigned, mul for "multiple languages", und for "undefined", and zxx for "no linguistic content, not applicable".eng corresponds to Part 2 eng and Part 1 enast corresponds to Part 2 ast but lacks a code in Part 1.aus in Part 2 and Part 5, which stands for Australian languages.Alpha-2 code space
"Alpha-2" codes (for codes composed of 2 letters of the ISO basic Latin alphabet) are used in ISO 639-1. When codes for a wider range of languages were desired, more than 2 letter combinations could cover (a maximum of 262 = 676), ISO 639-2 was developed using Alpha-3 codes (though the latter was formally published first).
Alpha-3 code space
"Alpha-3" codes (for codes composed of 3 letters of the ISO basic Latin alphabet) are used in ISO 639-2, ISO 639-3, and ISO 639-5. The number of languages and language groups that can be so represented is 263 = 17,576.
The common use of Alpha-3 codes by three parts of ISO 639 requires some coordination within a larger system.
Part 2 defines four special codes mis, mul, und, zxx, a reserved range qaa-qtz (20 × 26 = 520 codes) and has 23 double entries (the B/T codes). This sums up to 520 + 23 + 4 = 547 codes that cannot be used in part 3 to represent languages or in part 5 to represent language families or groups. The remainder is 17,576 – 547 = 17,029.
There are somewhere around six or seven thousand languages on Earth today. So those 17,029 codes are adequate to assign a unique code to each language, although some languages may end up with arbitrary codes that sound nothing like the traditional name(s) of that language.
Alpha-4 code space
"Alpha-4" codes (for codes composed of 4 letters of the ISO basic Latin alphabet) were proposed to be used in ISO 639-6, which has been withdrawn. The upper limit for the number of languages and dialects that can be represented is 264 = 456,976.