What are the differences between the ISO 639-1 and 639-2 code lists?
ISO 639-1, the two-character code, was devised primarily for use in terminology and includes identifiers for most of the major languages of the world that are not only most frequently represented in the total body of the world’s literature, but that are also among the most developed languages of the world, having specialized vocabulary and terminology. ISO 639-1 includes identifiers for a subset of the languages covered by ISO 639-2. ISO 639-2, the three-character code, was devised primarily for use in bibliography, as well as in terminology. It has a less restrictive scope than ISO 639-1, being devised to include identifiers for languages that are most frequently represented in the total body of the world’s literature, regardless of whether specialized terminologies exist in those languages or not. Because three characters allow for a much larger set of distinct identifiers, an alpha-3 code can accommodate a much larger set of languages. Indeed, ISO 639-2 does include significantly mo
