Title: Implementing the ISO 639-2 code for Sign Languages
Source: Michael Everson
Date: 2001-09-21

The code is a single 3-letter code, sgn. As necessary, other codes may be appended to that code (according to clause 4.4 of ISO 639-2) to specify different Sign Languages. Such extensions cannot be added to ISO 639-2 itself, as it does not register extended codes. However, extended codes may be registered with IETF according to RFC 3066 when warranted. The list of registered extended codes is available from IANA and an index to it is available.

Most of the Sign Languages in the tables below can be identified by the country in which they are used, by appending the 2-letter country code from ISO 3166-1. A number of them additionally require one of the regional extensions specified in ISO 3166-2 (where more than one Sign Language occurs in a country). A few of the extensions are language codes taken from ISO 639 or ISO 639-2; these are used where geographical delimitation is not feasible.

NOTE: The use of country and region codes is not intended to be comprehensive. American Sign Language (sgn-US) is used in Canada; Plains Sign Talk (sgn-US-SD) is not limited to the state of South Dakota. The codes are intended to be identifying, not encyclopaedic.

By convention, the language code is written in small letters, and the country code and regional extension are written in capital letters.

In each table, the first column (Name & Link) presents the name of the Sign Language and sometimes gives an HTML link to an external source for information about it. The second column (Acronym) gives a conventional acronym reported as an alternate name by the Deaf Action Committee for Sign Writing (DAC) or by the Summer Institute of Linguistics (SIL). The third column (SIL code) and fourth column (SIL country page) link to pages from the 13th edition of the SIL Ethnologue. In the fifth column (Code) is the registered or provisional RFC 1766 extended identifier. In the sixth column (Comment) a note is added to explain an extension when it consists of more than just the country code.

The list here is derived mostly from the Ethnologue's pages on Deaf Sign Languages and other Sign Languages. The SIL itself recognizes that for many of these languages, further investigation is required in order to ascertain their status. When Evertype, as a registrar for Sign Language extensions, has positive information regarding the uniqueness of a Sign Language, the code is registered with IETF and noted here in Table A. The remaining codes (in Table B) must be considered provisional until they are verified by experts. Appropriate verification entails the following:

1. A linguistic description (such as a formal grammar or dictionary)
2. Evidence of at least 5 additional documents in which the language is illustrated (printed or video)

A number of transcription systems exist to write Sign Languages for research purposes. Among these are Stokoe, HamNoSys, Bergmann, SignFont, Newkirk, Eshkol-Wahmann, Liddell Movement-Hold, SignPS, Labanotation, Benesh Movement Notation, numerous glossing systems, and life-like illustrations placed in special sequences. These transcription systems were not designed to be daily writing systems for Sign Languages; their sole purpose is to record linguistic analysis of signs for research studies.

The Sutton SignWriting system was designed to be a daily writing system for signers. At present, Deaf children, Deaf adults, and hearing signers in over 18 countries are writing their native signed languages with SignWriting symbols. It is being tested in schools and appears to raise literacy levels of born-deaf children, by providing a written base for their native (signed) language and the written (spoken) language of the majority in the countries in which they live. SignWriting is the only writing system used to publish written Sign Language literature, and offers a large number of publications of books, textbooks, and dictionaries, as well as the development of SignWriting software.

Documentation can be in any of these writing systems, and multimedia recordings such as video are also acceptable. The point is not to prefer any particular representation of a given Sign Language, but to determine if it is a unique Sign Language that cannot be identified with any other Sign Language. While there exists a French Canadian Sign Language (sgn-CA-QC) and a Nova Scotian Sign Language (sgn-CA-NS), there is no unique "Canadian Sign Language" (*sgn-CA) since this language is identical to American Sign Language (sgn-US). If Chadian Sign Language (sgn-TD) turned out also to be identical to American Sign Language (SIL says it shows ASL influence), it would be incorrect to provide a unique code for it.

Table A: Registered Codes

Name & link	Acronym	SIL code	SIL country page	Code	Comment
American Sign Language	ASL	ASE	USA, Canada	sgn-US
Belgian-Flemish Sign Language		BVS	Belgium	sgn-BE-nl	Belgium & Dutch (language)
Belgian-French Sign Language		BVS	Belgium	sgn-BE-fr	Belgium & French (language)
Brazilian Sign Language	LIBRAS	BZS	Brazil	sgn-BR
British Sign Language	BSL	BHO	United Kingdom	sgn-GB
Colombian Sign Language	LSC	CSN	Colombia	sgn-CO
Danish Sign Language	DTS	DSL	Denmark	sgn-DK
Dutch Sign Language	NGT	DSE	Netherlands	sgn-NL
French Sign Language	LSF	FSL	France	sgn-FR
German Sign Language	DGS	GSG	Germany	sgn-DE
Greek Sign Language		GSS	Greece	sgn-GR
Irish Sign Language	ISL	ISG	Ireland	sgn-IE
Italian Sign Language	LIS	ISE	Italy	sgn-IT
Japanese Sign Language		JSL	Japan	sgn-JP
Mexican Sign Language	LSM	MFS	Mexico	sgn-MX
Nicaraguan Sign Language	ISN	NCS	Nicaragua	sgn-NI
Norwegian Sign Language	NTS	NSL	Norway	sgn-NO
Portuguese Sign Language	LGP	PSR	Portugal	sgn-PT
South African Sign Language		SFS	South Africa	sgn-ZA
Spanish Sign Language	LSE	SSP	Spain	sgn-ES
Swedish Sign Language	STS	SWL	Sweden	sgn-SE
Swiss-German Sign Language	DSGS	SGG	Switzerland	sgn-CH-de	Switzerland & German (language)

Table B: Provisional Codes

Table C: Signed Spoken Languages

Name & Link	Acronym	SIL Code	SIL Country	639-2 + ext. (proposed)	Comment
Signed Afrikaans			South Africa	sgn-afr-ZA
Signed Chinese			Taiwan	sgn-chi-TW
Signed Danish			Denmark	sgn-dan-DK
Signed Dutch			Belgium	sgn-dut-BE
Signed Dutch			Netherlands	sgn-dut-NL
Signed English			United Kingdom	sgn-eng-GB
Signed English			Ireland	sgn-eng-IE
Signed English			USA	sgn-eng-US
Signed Finnish			Finland	sgn-fin-FI
Signed French			Belgium	sgn-fre-BE
Signed French			Canada	sgn-fre-CA
Signed French			France	sgn-fre-FR
Signed Japanese			Japan	sgn-jpn-JP
Signed Norwegian			Norway	sgn-nor-NO
Signed Portuguese			Portugal	sgn-por-PT
Signed Swedish			Sweden	sgn-swe-SE