ISO 639 is a standardized nomenclature used to classify all known languages. Each language is assigned a 3 letter abbreviation, amended in later versions of the nomenclature. The system is highly useful for linguists and ethnographers to categorize the languages spoken on a regional basis, and to compute analysis in the field of lexicostatistics. ISO 639 has five code lists.
This table lists all of:
* ISO 639-1: two-letter codes, one per language or macrolanguage
And some of:
* ISO 639-2/T: three-letter codes, for the same languages as 639-1
* ISO 639-2/B: three-letter codes, mostly the same as 639-2/T, but with some codes derived from English names rather than native names of languages. In the following table, these differing codes are highlighted in boldface.
* ISO 639-3: three-letter codes, the same as 639-2/T for languages, but with distinct codes for each dialect of macrolanguages