Language codes are a combination of the ISO 639-1 language codes and the ISO 3166-1 country codes.
Note: While we normally follow the above standard we have one known instance where we send "zh_Hant_HK" as a language. This should be interpreted as Traditional Chinese, Hong Kong.
The format is this. lc[_cc[_desc]]. The parts in brackets are optional. lc is the 2 character language code. cc is the two character country code. desc is a further qualifier.
Here is the full list of supported country codes as of the time this was written.
| Code | Value | 
|---|---|
| ar_001 | Arabic | 
| ar_EG | Arabic (Egypt) | 
| cs_CZ | Czech | 
| da_DK | Danish | 
| de_AT | German (Austria) | 
| de_CH | German (Switzerland) | 
| de_DE | German | 
| el_GR | Greek | 
| en_AU | English | 
| en_CA | English (Canada) | 
| en_GB | English (Great Britain) | 
| en_HK | English (Hong Kong) | 
| en_IE | English (Ireland) | 
| en_IN | English (India) | 
| en_MY | English (Malaysia) | 
| en_NZ | English (New Zealand) | 
| en_PH | English (Philippines) | 
| en_SG | English (Singapore) | 
| en_US | English (United States) | 
| en_ZA | English (South Africa) | 
| es_AR | Spanish (Argentina) | 
| es_CL | Spanish (Chile) | 
| es_CO | Spanish (Columbia) | 
| es_ES | Spanish (Spain) | 
| es_MX | Spanish (Mexico) | 
| es_PE | Spanish (Peru) | 
| es_VE | Spanish (Venezuela) | 
| fi_FI | Finnish | 
| fr_BE | French (Belgium) | 
| fr_CA | French (Canada) | 
| fr_CH | French (Switzerland) | 
| fr_FR | French (France) | 
| he_IL | Hebrew | 
| hu_HU | Hungarian | 
| id_ID | Indonesian | 
| it_CH | Italian (Switzerland) | 
| it_IT | Italian (Italy) | 
| ja_JP | Japanese (Japan) | 
| ko_KR | Korean (Korea) | 
| nb_NO | Norwegian | 
| nl_BE | Dutch (Belgium) | 
| nl_NL | Dutch (Netherlands) | 
| pl_PL | Polish | 
| pt_BR | Portuguese (Brazil) | 
| pt_PT | Portuguese (Portugal) | 
| ru_RU | Russian (Russia) | 
| sk_SK | Slovak | 
| sr_Latn_RS | Serbian | 
| sv_SE | Swedish (Sweden) | 
| th_TH | Thai | 
| tr_TR | Turkish | 
| vi_VN | Vietnamese | 
| zh_CN | Chinese (China) | 
| zh_Hant_HK | Traditional Chinese (Hong Kong) | 
| zh_TW | Chinese (Taiwan) |