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 ISO/TC 37/SC 2 (International Organization for Standardization, Technical Committee 37, Subcommittee 2: Terminographical and lexicographical working methods – later renamed to Terminology workflow and language coding). It contained four-letter codes that denote variants of languages and language families. This allowed one to differentiate between, for example, historical (glvx) versus revived (rvmx) 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 ISO 639-6 was published on 17 November 2009, and withdrawn on 25 November 2014 because of concerns about its usefulness and maintainability.[1][2] The database also links each language and family to its principal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
Language(s) ISO 639-3
scope
ISO 639-3
type
ISO 639-2/3
code
ISO 639-2/5
code
  English Individual Living eng  
emen Early Modern English (ca. 1485 – ca. 1660) Individual Living (eng)  
emse Early Midland and South Eastern Middle English Individual Historic (enm)  
meng Middle English (ca. 1066 – ca. 1350) Individual Historic enm  
ango Anglo Saxon (Old English) (ca. 450 – ca. 1250) Individual Historic ang  
angl Anglic Collective     (gmw)
nsea North Sea (Ingvaeonic) Collective     (gmw)
gmcw West Germanic Collective     gmw
grmc Germanic Collective     gem
ineu Indo-European Collective     ine
wrld World (undetermined) 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 variant ISO 639-3
scope
ISO 639-3
type
ISO 639-2/3
code
ISO 15924
code
  Turkish, Ottoman (1500–1928) Individual Historic ota  
otaa Turkish, Ottoman (1500–1928), Armenian script Individual Historic ota Armn
otah Turkish, Ottoman (1500–1928), Hellenic script Individual Historic ota Grek
otap Turkish, Ottoman (1500–1928), Perso-Arabic script Individual Historic ota Arab
  1. ^ "ISO 639-6:2009". ISO. Archived from the original on 2018-10-31. Retrieved 2018-10-31.
  2. ^ Constable, Peter (21 October 2014). "FYI: withdrawal of ISO 639-6". Archived from the original on 21 August 2019. Retrieved 21 August 2019.