The POEditor language list follows the ISO 639-1:2002 list, and includes other official country languages as well.
In case you need to localize your app or website strings into a language which is not in our language list, you can add a custom language.
Search for your language in the language menu and if you can't find it, click on the Add custom language link at the bottom of the language list, then give it a unique name and code.
If you're using localization files which support plural forms, choose the plural rules for your custom language from a language in our list, which has the same number of plurals. If you don't work with plural strings, choose any language for plurals (this field is mandatory).