| Abbreviation | Definition |
|---|---|
| OBIS | Ocean Biogeographic Information System |
| OBNC | Outer Banks North Carolina |
| OGNB | Ontario Geographic Names Board |
| OGNB | Oregon Geographic Names Board |
| ORM | Oak Ridges Moraine |
| OSMF | OpenStreetMap Foundation |
| PGI | Protected Geographical Indication |
| PGIS | Participatory Geographic Information Systems |
| PGIS | Participatory Geographical Information Systems |
| PGIS | Politics Geography and International Studies |
| PHCP | Permanent Heterogeneous Continuous Pore-system |
| PHG | Progress in Human Geography |
| PHPB | Polar High Pressure Belt |
| PLS | Pratice Land Survey |
| POMLAD | Preveling winds, Ocean currents, Mountain barriers, Latitude, Altitude, Distance |
| PPG | Progress in Physical Geography |
| PRS | Practice on Remote Sensing |
| PSGC | Philippine Standard Geographic Classification |
| PSGC | Philippine Standard Geographic Code |
| QDGC | Quarter Degree Grid Cells |