You have probably seen 2-letter codes referring to languages, e.g. FR, EN, DE for French, English and German respectively.
Such codes used to be rather arbitrary (GE or DE or German? DU or NL for Dutch? Is PO Polish or Portuguese, etc.) but more and more companies are now using standardized codes, in accordance with ISO 639.
2-letter codes are covered by ISO 639-1, and are mostly based on the language name in the local language (so it’s DE for Deutsch, NL for nederlands, etc.). The standard also serves to resolve ambiguities like PO (Polish = PL, Portuguese = PT and PO is not used).
Here are the codes for some major languages (actually the ones we see the biggest translation demand for):
|Code||Language||Comments (some diacritics may be missing)|
|BG||Bulgarian||Blgarski ezik (Cyrillic script български език)|
|CS||Czech||The digraph cz- is English is odd. It is used in no other word and does not appear in Czech.|
|DA||Danish||Not to be confused with the DK used on car number plates|
|EL||Greek||Ellinika in Greek – Ελληνικά|
|FI||Finnish||Odd, since in Finnish it’s suomen kieli|
|HU||Hungarian||Odd, since it’s Magyar in Hungarian|
|JA||Japanese||Another anomaly: Nippon go in Japanese 日本語|
|KO||Korean||Han in Korean 한국어|
|NO||Norwegian||Norsk, but the literary variety is called Norsk bokmal (NB)|
|RU||Russian||Russkii yazik (русский язык – Cyrillic alphabet)|
|SV||Swedish||Svenska (SW = Swahili)|
|ZH||Chinese||中文 – Zhong wen, i.e. Mandarin Chinese. You sometimes see ZH-S and ZH-T for simplified and traditional forms respectively, though this is not part of the ISO standard.|
For a complete list, see for example Wikipedia.