This section details the languages currently covered by the specifications. The first column defines the cannonical ordering of the languages. In the current specification they are grouped together by language family. The codes follow ISO 639 two-letter codes for languages. For each language we note which language family it belongs to and the link the the respective entry in the Ethnologue database.
| P | Code | Name | Family | Links |
| 1 | en | English | Germanic | Ethnologue |
| 2 | ro | Romanian | Romance | Ethnologue |
| 3 | pl | Polish | West Slavic | Ethnologue |
| 4 | cs | Czech | West Slavic | Ethnologue |
| 5 | sk | Slovak | West Slavic | Ethnologue |
| 6 | sl | Slovene | South West Slavic | Ethnologue |
| 7 | sl-rozaj | Resian | dialect of Slovene | IANA |
| 8 | hr | Croatian | South West Slavic | Ethnologue |
| 9 | sr | Serbian | South West Slavic | Ethnologue |
| 10 | bs | Bosnian | South West Slavic | Ethnologue |
| 11 | ru | Russian | East Slavic | Ethnologue |
| 12 | uk | Ukrainian | East Slavic | Ethnologue |
| 13 | mk | Macedonian | South East Slavic | Ethnologue |
| 14 | bg | Bulgarian | South East Slavic | Ethnologue |
| 15 | fa | Persian | Indo-Iranian | Ethnologue |
| 16 | et | Estonian | Finno-Ugric | Ethnologue |
| 17 | hu | Hungarian | Finno-Ugric | Ethnologue |
| 18 | ce | Chechen | Caucasian | Ethnologue |