| Abbreviation | Definition |
|---|---|
| SHN | Shan |
| SID | Sidamo |
| SIN | Singhalese |
| SIO | Siouan Languages |
| SIT | Sino-Tibetan (Other) |
| SKK | Simple Kana to Kanji |
| SLA | Slavic (Other) |
| SLK | Slovak |
| SLO | Slovak |
| SLV | Slovenian |
| SMI | Sami Languages |
| SMO | Samoan |
| SNA | Shona |
| SND | Sindhi |
| SNH | Sinhalese |
| SNI | SENSI: an extinct language of Peru |
| SOG | Sogdian |
| SOM | Cushitic: East: Somali: SOMALI |
| SOM | Somali |
| SON | Songhai |