Bukkit

Language Codes

af - Afrikaans
ak - Akan
sq - Albanian
am - Amharic
ar - Arabic
hy - Armenian
az - Azerbaijani
eu - Basque
be - Belarusian
bem - Bemba
bn - Bengali
bh - Bihari
bs - Bosnian
br - Breton
bg - Bulgarian
km - Cambodian
ca - Catalan
chr - Cherokee
ny - Chichewa
zh_CN - Chinese (Simplified)
zh_TW - Chinese (Traditional)
co - Corsican
hr - Croatian
cs - Czech
da - Danish
nl - Dutch
en - English
eo - Esperanto
et - Estonian
ee - Ewe
fo - Faroese
tl - Filipino
fi - Finnish
fr - French
fy - Frisian
gaa - Ga
gl - Galician
ka - Georgian
de - German
el - Greek
gn - Guarani
gu - Gujarati
ht - Haitian Creole
ha - Hausa
haw - Hawaiian
iw - Hebrew
hi - Hindi
hu - Hungarian
is - Icelandic
ig - Igbo
id - Indonesian
ia - Interlingua
ga - Irish
it - Italian
ja - Japanese
jw - Javanese
kn - Kannada
kk - Kazakh
rw - Kinyarwanda
rn - Kirundi
kg - Kongo
ko - Korean
kri - Krio (Sierra Leone)
ku - Kurdish
ckb - Kurdish (Soranî)
ky - Kyrgyz
lo - Laothian
la - Latin
lv - Latvian
ln - Lingala
lt - Lithuanian
loz - Lozi
lg - Luganda
ach - Luo
mk - Macedonian
mg - Malagasy
ms - Malay
ml - Malayalam
mt - Maltese
mi - Maori
mr - Marathi
mfe - Mauritian Creole
mo - Moldavian
mn - Mongolian
sr_ME - Montenegrin
ne - Nepali
pcm - Nigerian Pidgin
nso - Northern Sotho
no - Norwegian
nn - Norwegian (Nynorsk)
oc - Occitan
or - Oriya
om - Oromo
ps - Pashto
fa - Persian
pl - Polish
pt_BR - Portuguese (Brazil)
pt_PT - Portuguese (Portugal)
pa - Punjabi
qu - Quechua
ro - Romanian
rm - Romansh
nyn - Runyakitara
ru - Russian
gd - Scots Gaelic
sr - Serbian
sh - Serbo-Croatian
st - Sesotho
tn - Setswana
crs - Seychellois Creole
sn - Shona
sd - Sindhi
si - Sinhalese
sk - Slovak
sl - Slovenian
so - Somali
es - Spanish
es_419 - Spanish (Latin American)
su - Sundanese
sw - Swahili
sv - Swedish
tg - Tajik
ta - Tamil
tt - Tatar
te - Telugu
th - Thai
ti - Tigrinya
to - Tonga
lua - Tshiluba
tum - Tumbuka
tr - Turkish
tk - Turkmen
tw - Twi
ug - Uighur
uk - Ukrainian
ur - Urdu
uz - Uzbek
vi - Vietnamese
cy - Welsh
wo - Wolof
xh - Xhosa
yi - Yiddish
yo - Yoruba
zu - Zulu

Non Official language file

xx_elmer - Elmer Fudd
xx_bork - Bork, bork, bork!
xx_hacker - Hacker
xx_lol_US - Kittenz
xx_klingon Klingon
xx_pirate - Pirate

This list is a reference for making translations, it does not mean there all added to the uSkyblock plugin.