This is a list of ISO 639 codes and IETF language tags (BCP 47) for individual constructed languages, complete as of April 2019.

ISO 639-2 and ISO 639-5 also have the code art for other artificial languages.[1] The BCP 47 subtag x can be used to create a suitable private use tag for any constructed language that has not been assigned an official language tag (e.g., art-x-solresol could be used for Solresol).

The old SIL language identifiers (usually written in capitals) are officially obsolete and should no longer be used. They formed the basis of the ISO 639-3 language codes, but some SIL identifiers that had been retired before the establishment of ISO 639-3 were later assigned to different languages within ISO.

The IANA Language Subtag Registry (for IETF’s language tags defined in BCP 47) was updated on 29 July 2009 to include all ISO 639-3 and ISO 639-5 identifiers in use at that time.

List of codesEdit

Language ISO
BCP 47[4] MultiTree[5] SIL
Afrihili   afh afh afh afh  
Balaibalan     zba zba    
Blissymbols   zbl zbl zbl zbl  
Brithenig     bzt bzt bzt  
Dutton Speedwords     dws dws dws  
Enochian       i-enochian[note 1]    
Esperanto eo epo epo eo epo ESP
Europanto     eur[note 2][6]   eur[7] EUR
Ido io ido ido io ido[8]  
Interglossa     igs igs igs  
Interlingua (IALA) ia ina ina ia ina INR
Interlingue (former Occidental) ie ile ile
occ[note 3][9]
ie ile  
Klingon   tlh tlh tlh
i-klingon[note 1]
Kotava     avk avk avk  
Láadan     ldn ldn ldn  
Lingua Franca Nova     lfn lfn lfn  
Lojban   jbo jbo jbo
art-lojban[note 1]
Medefaidrin     dmf dmf 1eo  
Na'vi         08n  
Neo     neu neu neu  
Novial     nov nov nov  
Quenya     qya qya qya  
Romanova     rmv rmv rmv  
Sindarin     sjn sjn sjn  
Talossan     tzl tzl tzl  
Volapük vo vol vol vo vol  

See alsoEdit


  1. ^ a b c The BCP 47 language tags i-enochian, i-klingon and art-lojban are old tags that were grandfathered in. The last two are deprecated in preference to the later three-letter codes.
  2. ^ The ISO 639-3 standard previously included the code eur for Europanto, which was retired on 2009-01-16, with the reason “Nonexistent”.
  3. ^ ISO 639-3 used to have the code occ for Occidental. This was retired on 18 July 2007, because Occidental is just another name for Interlingue, which has the code ile.


  1. ^ "639 Identifier Documentation: art". 2019-02-03.
  2. ^ a b "Codes for the Representation of Names of Languages". Library of Congress. 2013-01-11.
  3. ^ a b c "ISO 639 code tables: constructed". Retrieved 2019-02-03.
  4. ^ "IANA Language Subtag Registry". 2018-11-30.
  5. ^ "Constructed Languages". MultiTree. 2019-02-03.
  6. ^ "639 Identifier Documentation: eur". 2019-02-03.
  7. ^ "Europanto". MultiTree.
  8. ^ "Ido". MultiTree.
  9. ^ "639 Identifier Documentation: occ". 2019-02-03.