For Z39.50 definitions that specify the use of a language code and that refer to this page (for example, the value of the term corresponding to Utility attribute set Access Point Attribute 'Language of Record', as well as the value of the Utility Set attribute value Language), language codes should be taken from the second column in the table below (Three Character Bibliographic Code -- ISO 639-2/B). When clients use other codes, for example the 2-character codes from the fourth column, server behavior is not specified (the server may accept and process the alternative code or may fail the request).

(Table provided by Michael Everson of Everson Gunn Teoranta)

Three Character Terminological Code (ISO 639-2/T)	Three Character Bibliographic Code (ISO 639-2/B)	Language	Two Character Code (ISO 639-1)
aar	aar	Afar	aa
abk	abk	Abkhazian	ab
ace	ace	Achinese
ach	ach	Acoli
ada	ada	Adangme
afa	afa	Afro-Asiatic (Other)
afh	afh	Afrihili
afr	afr	Afrikaans	af
ajm	ajm	Aljamia
aka	aka	Akan
akk	akk	Akkadian
ale	ale	Aleut
alg	alg	Algonquian languages
amh	amh	Amharic	am
ang	ang	English, Old (ca. 450-1100)
apa	apa	Apache languages
ara	ara	Arabic	ar
arc	arc	Aramaic
arn	arn	Araucanian
arp	arp	Arapaho
art	art	Artificial (Other)
arw	arw	Arawak
asm	asm	Assamese	as
ath	ath	Athapascan languages
aus	aus	Australian languages
ava	ava	Avaric
ave	ave	Avestan
awa	awa	Awadhi
aym	aym	Aymara	ay
aze	aze	Azerbaijani	az
bad	bad	Banda
bai	bai	Bamileke languages
bak	bak	Bashkir	ba
bal	bal	Baluchi
bam	bam	Bambara
ban	ban	Balinese
bas	bas	Basa
bat	bat	Baltic (Other)
bej	bej	Beja
bel	bel	Belarusian	be
bem	bem	Bemba
ben	ben	Bengali	bn
ber	ber	Berber (Other)
bho	bho	Bhojpuri
bih	bih	Bihari	bh
bik	bik	Bikol
bin	bin	Bini
bis	bis	Bislama	bi
bla	bla	Siksika
bnt	bnt	Bantu (Other)
bod	tib	Tibetan	bo
bra	bra	Braj
bre	bre	Breton	br
btk	btk	Batak (Indonesia)
bua	bua	Buriat
bug	bug	Buginese
bul	bul	Bulgarian	bg
cad	cad	Caddo
cai	cai	Central American Indian (Other)
car	car	Carib
cat	cat	Catalan	ca
cau	cau	Caucasian (Other)
ceb	ceb	Cebuano
cel	cel	Celtic (Other)
ces	cze	Czech	cs
cha	cha	Chamorro
chb	chb	Chibcha
che	che	Chechen
chg	chg	Chagatai
chk	chk	Chuukese
chm	chm	Mari
chn	chn	Chinook jargon
cho	cho	Choctaw
chp	chp	Chipewyan
chr	chr	Cherokee
chu	chu	Church Slavic
chv	chv	Chuvash
chy	chy	Cheyenne
cmc	cmc	Chamic languages
cop	cop	Coptic
cor	cor	Cornish	kw
cos	cos	Corsican	co
cpe	cpe	Creoles and pidgins, English-based (Other)
cpf	cpf	Creoles and pidgins, French-based (Other)
cpp	cpp	Creoles and pidgins, Portuguese-based (Other)
cre	cre	Cree
crp	crp	Creoles and pidgins (Other)
cus	cus	Cushitic (Other)
cym	wel	Welsh	cy
dak	dak	Dakota
dan	dan	Danish	da
day	day	Dayak
del	del	Delaware
den	den	Slave (Athapascan)
deu	ger	German	de
dgr	dgr	Dogrib
din	din	Dinka
div	div	Divehi
doi	doi	Dogri
dra	dra	Dravidian (Other)
dua	dua	Duala
dum	dum	Dutch, Middle (ca. 1050-1350)
dyu	dyu	Dyula
dzo	dzo	Dzongkha	dz
efi	efi	Efik
egy	egy	Egyptian (Ancient)
eka	eka	Ekajuk
ell	gre	Greek, Modern (post 1453)	el
elx	elx	Elamite
eng	eng	English	en
enm	enm	English, Middle (1100-1500)
epo	epo	Esperanto	eo
est	est	Estonian	et
eth	eth	Ethiopic
eus	baq	Basque	eu
ewe	ewe	Ewe
ewo	ewo	Ewondo
fan	fan	Fang
fao	fao	Faroese	fo
fas	per	Persian	fa
fat	fat	Fanti
fij	fij	Fijian	fj
fin	fin	Finnish	fi
fiu	fiu	Finno-Ugrian (Other)
fon	fon	Fon
fra	fre	French	fr
frm	frm	French, Middle (ca. 1400-1600)
fro	fro	French, Old (842-ca. 1400)
fry	fry	Frisian	fy
ful	ful	Fulah
fur	fur	Friulian
gaa	gaa	Ga
gay	gay	Gayo
gba	gba	Gbaya
gem	gem	Germanic (Other)
gez	gez	Geez
gil	gil	Gilbertese
gla	gla	Gaelic (Scots)	gd
gle	gle	Irish	ga
glg	glg	Gallegan	gl
glv	glv	Manx	gv
gmh	gmh	German, Middle High (ca. 1050-1500)
goh	goh	German, Old High (ca. 750-1050)
gon	gon	Gondi
gor	gor	Gorontalo
got	got	Gothic
grb	grb	Grebo
grc	grc	Greek, Ancient (to 1453)
grn	grn	Guarani	gn
guj	guj	Gujarati	gu
gwi	gwi	Gwich'in
hai	hai	Haida
hau	hau	Hausa	ha
haw	haw	Hawaiian
heb	heb	Hebrew	he/iw
her	her	Herero
hil	hil	Hiligaynon
him	him	Himachali
hin	hin	Hindi	hi
hit	hit	Hittite
hmn	hmn	Hmong
hmo	hmo	Hiri Motu
hrv	scr	Croatian	hr
hun	hun	Hungarian	hu
hup	hup	Hupa
hye	arm	Armenian	hy
iba	iba	Iban
ibo	ibo	Igbo
ijo	ijo	Ijo
iku	iku	Inuktitut	iu
ile	ile	Interlingue	ie
ilo	ilo	Iloko
ina	ina	Interlingua (International Auxilary Language Association)	ia
inc	inc	Indic (Other)
ind	ind	Indonesian	id/in
ine	ine	Indo-European (Other)
ipk	ipk	Inupiak	ik
ira	ira	Iranian (Other)
iro	iro	Iroquoian languages
isl	ice	Icelandic	is
ita	ita	Italian	it
jaw	jav	Javanese	jw
jpn	jpn	Japanese	ja
jpr	jpr	Judeo-Persian
jrb	jrb	Judeo-Arabic
kaa	kaa	Kara-Kalpak
kab	kab	Kabyle
kac	kac	Kachin
kal	kal	Kalaallisut	kl
kam	kam	Kamba
kan	kan	Kannada	kn
kar	kar	Karen
kas	kas	Kashmiri	ks
kat	geo	Georgian	ka
kau	kau	Kanuri
kaw	kaw	Kawi
kaz	kaz	Kazakh	kk
kha	kha	Khasi
khi	khi	Khoisan (Other)
khm	khm	Khmer	km
kho	kho	Khotanese
kik	kik	Kikuyu
kin	kin	Kinyarwanda	rw
kir	kir	Kirghiz	ky
kmb	kmb	Kimbundu
kok	kok	Konkani
kom	kom	Komi
kon	kon	Kongo
kor	kor	Korean	ko
kos	kos	Kosraean
kpe	kpe	Kpelle
kro	kro	Kru
kru	kru	Kurukh
kua	kua	Kuanyama
kum	kum	Kumyk
kur	kur	Kurdish	ku
kut	kut	Kutenai
lad	lad	Ladino
lah	lah	Lahnda
lam	lam	Lamba
lao	lao	Lao	lo
lat	lat	Latin	la
lav	lav	Latvian	lv
lez	lez	Lezghian
lin	lin	Lingala	ln
lit	lit	Lithuanian	lt
lol	lol	Mongo
loz	loz	Lozi
ltz	ltz	Lktzeburgesch	lb
lua	lua	Luba-Lulua
lub	lub	Luba-Katanga
lug	lug	Ganda
lui	lui	Luiseno
lun	lun	Lunda
luo	luo	Luo (Kenya and Tanzania)
lus	lus	Lushai
mad	mad	Madurese
mag	mag	Magahi
mah	mah	Marshall
mai	mai	Maithili
mak	mak	Makasar
mal	mal	Malayalam	ml
man	man	Mandingo
map	map	Austronesian (Other)
mar	mar	Marathi	mr
mas	mas	Masai
mdr	mdr	Mandar
men	men	Mende
mga	mga	Irish, Middle (900-1200)
mic	mic	Micmac
min	min	Minangkabau
mis	mis	Miscellaneous languages
mkd	mac	Macedonian	mk
mkh	mkh	Mon-Khmer (Other)
mlg	mlg	Malagasy	mg
mlt	mlt	Maltese	mt
mni	mni	Manipuri
mno	mno	Manobo languages
moh	moh	Mohawk
mol	mol	Moldavian	mo
mon	mon	Mongolian	mn
mos	mos	Mossi
mri	mao	Maori	mi
msa	may	Malay	ms
mul	mul	Multiple languages
mun	mun	Munda languages
mus	mus	Creek
mwr	mwr	Marwari
mya	bur	Burmese	my
myn	myn	Mayan languages
nah	nah	Nahuatl
nai	nai	North American Indian (Other)
nau	nau	Nauru	na
nav	nav	Navajo
nbl	nbl	Ndebele, South
nde	nde	Ndebele, North
ndo	ndo	Ndonga
nep	nep	Nepali	ne
new	new	Newari
nia	nia	Nias
nic	nic	Niger-Kordofanian (Other)
niu	niu	Niuean
nld	dut	Dutch	nl
non	non	Norse, Old
nor	nor	Norwegian	no
nso	nso	Sotho, Northern
nub	nub	Nubian languages
nya	nya	Nyanja
nym	nym	Nyamwezi
nyn	nyn	Nyankole
nyo	nyo	Nyoro
nzi	nzi	Nzima
oci	oci	Occitan (post 1500)	oc
oji	oji	Ojibwa
ori	ori	Oriya
orm	orm	Oromo	om
osa	osa	Osage
oss	oss	Ossetic
ota	ota	Turkish, Ottoman (1500-1928)
oto	oto	Otomian languages
paa	paa	Papuan (Other)
pag	pag	Pangasinan
pal	pal	Pahlavi
pam	pam	Pampanga
pan	pan	Panjabi	pa
pap	pap	Papiamento
pau	pau	Palauan
peo	peo	Persian, Old (ca. 600-400 B.C.)
phi	phi	Philippine (Other)
phn	phn	Phoenician
pli	pli	Pali
pol	pol	Polish	pl
pon	pon	Pohnpeian
por	por	Portuguese	pt
pra	pra	Prakrit languages
pro	pro	Provengal, Old (to 1500)
pus	pus	Pushto	ps
qaa-qtz	qaa-qtz	reserved for local use
que	que	Quechua	qu
raj	raj	Rajasthani
rap	rap	Rapanui
rar	rar	Rarotongan
roa	roa	Romance (Other)
roh	roh	Rhaeto-Romance	rm
rom	rom	Romany
ron	rum	Romanian	ro
run	run	Rundi	rn
rus	rus	Russian	ru
sad	sad	Sandawe
sag	sag	Sango	sg
sai	sai	South American Indian (Other)
sal	sal	Salishan languages
sam	sam	Samaritan Aramaic
san	san	Sanskrit	sa
sas	sas	Sasak
sat	sat	Santali
sco	sco	Scots
sel	sel	Selkup
sem	sem	Semitic (Other)
sga	sga	Irish, Old (to 900)
shn	shn	Shan
sid	sid	Sidamo
sin	sin	Sinhalese	si
sio	sio	Siouan languages
sit	sit	Sino-Tibetan (Other)
sla	sla	Slavic (Other)
slk	slo	Slovak	sk
slv	slv	Slovenian	sl
smi	smi	Sami languages	se
smo	smo	Samoan	sm
sna	sna	Shona	sn
snd	snd	Sindhi	sd
snk	snk	Soninke
sog	sog	Sogdian
som	som	Somali	so
son	son	Songhai
sot	sot	Sotho, Southern	st
spa	spa	Spanish	es
sqi	alb	Albanian	sq
srd	srd	Sardinian
srp	scc	Serbian	sr
srr	srr	Serer
ssa	ssa	Nilo-Saharan (Other)
ssw	ssw	Swati	ss
suk	suk	Sukuma
sun	sun	Sundanese	su
sus	sus	Susu
sux	sux	Sumerian
swa	swa	Swahili	sw
swe	swe	Swedish	sv
syr	syr	Syriac
tah	tah	Tahitian
tai	tai	Tai (Other)
tam	tam	Tamil	ta
tat	tat	Tatar	tt
tel	tel	Telugu	te
tem	tem	Timne
ter	ter	Tereno
tet	tet	Tetum
tgk	tgk	Tajik	tg
tgl	tgl	Tagalog	tl
tha	tha	Thai	th
tig	tig	Tigre
tir	tir	Tigrinya
tiv	tiv	Tiv
tkl	tkl	Tokelau
tli	tli	Tlingit
tmh	tmh	Tamashek
tog	tog	Tonga (Nyasa)
ton	ton	Tonga (Tonga Islands)
tpi	tpi	Tok Pisin
tsi	tsi	Tsimshian
tsn	tsn	Tswana	tn
tso	tso	Tsonga	ts
tuk	tuk	T|rkmen	tk
tum	tum	Tumbuka
tur	tur	Turkish
tut	tut	Altaic (Other)
tvl	tvl	Tuvalu
twi	twi	Twi	tw
tyv	tyv	Tuvinian
uga	uga	Ugaritic
uig	uig	Uighur	ug
ukr	ukr	Ukrainian	uk
umb	umb	Umbundu
und	und	Undetermined
urd	urd	Urdu	ur
uzb	uzb	Uzbek	uz
vai	vai	Vai
ven	ven	Venda
vie	vie	Vietnamese	vi
vol	vol	Volap|k	vo
vot	vot	Votic
wak	wak	Wakashan languages
wal	wal	Walamo
war	war	Waray
was	was	Washo
wen	wen	Sorbian languages
wol	wol	Wolof	wo
xho	xho	Xhosa	xh
yao	yao	Yao
yap	yap	Yapese
yid	yid	Yiddish	yi/ji
yor	yor	Yoruba
ypk	ypk	Yupik languages
zap	zap	Zapotec
zen	zen	Zenaga
zha	zha	Zhuang	za
zho	chi	Chinese	zh
znd	znd	Zande
zul	zul	Zulu	zu
zun	zun	Zuqi