| Abbreviation | Definition |
|---|---|
| OSS | Ossetic |
| OTA | Turkish, Ottoman (1500 - 1928) |
| OTO | Otomian Languages |
| OYK | Shallow abal, Australian Aboriginal language |
| PAA | Papuan- Australian (Other) |
| PAG | Pangasinan |
| PAL | Pahlavi |
| PAM | Pampanga |
| PAN | Panjabi |
| PAP | Papiamento |
| PAU | Palauan |
| PDE | Present Day English |
| PEO | Persian, Old (ca. 600 - 400 B. C.) |
| PER | Persian |
| PHN | Phoenician |
| PIE | Proto Indo European |
| PIS | Plains Indian Sign Language |
| PLI | Pali |
| POJ | LOWER POKOMO: A language of Kenya |
| POL | Polish |