ISO 639-6


ISO 639-6, Codes for the representation of names of languages — Part 6: Alpha-4 code for comprehensive coverage of language variants, was a proposed international standard in the ISO 639 series, developed by . It contained four-letter codes that denote variants of languages and language families. This allowed one to differentiate between, for example, historical versus revived Manx, while ISO 639-3 only includes glv for Manx.
The data supporting ISO 639-6 was researched and compiled by the ISO's registration authority GeoLang. ISO 639-6 was published on 17November 2009, and withdrawn on 25November 2014 because of concerns about its usefulness and maintainability. The database also links each language and family to its principal ancestor, allowing the user to follow the classification of various languages. For example, the codes and ancestry of English is given below:
ISO 639-6
code		LanguageISO 639-3
scope		ISO 639-3
type		ISO 639-2/3
code		ISO 639-2/5
code
EnglishIndividualLivingeng
emenEarly Modern English IndividualLiving'
emseEarly Midland and South Eastern Middle EnglishIndividualHistoric'
mengMiddle English IndividualHistoricenm
angoAnglo Saxon IndividualHistoricang
anglAnglicCollective '
nseaNorth Sea Collective '
gmcwWest GermanicCollective gmw
grmcGermanicCollective gem
ineuIndo-EuropeanCollective ine
wrldWorld Special und

The database differentiated between different scripts used for the same language. For example, a number of different scripts were used in the Ottoman Empire and as a result the Ottoman Turkish language has been categorized as follows:
ISO 639-6
code		Language or variantISO 639-3
scope		ISO 639-3
type		ISO 639-2/3
code		ISO 15924
code
Turkish, Ottoman IndividualHistoricota
otaaTurkish, Ottoman, Armenian scriptIndividualHistoricotaArmn
otahTurkish, Ottoman, Hellenic scriptIndividualHistoricotaGrek
otapTurkish, Ottoman, Perso-Arabic scriptIndividualHistoricotaArab