| Abbreviation | Definition |
|---|---|
| ORK | Order of the Rebel Knights |
| OS | Oh Starcraft |
| OSD | Order for Snapes Defence |
| OTC | Order Through Chaos |
| OTO | Of Terrestrial Origin |
| OVNI | Objet Volant Non Identifié (French: Unidentified Flying Object) |
| OVS | Original Vampire Slayer |
| OWL | Ordinary Wizarding Levels |
| OZ | Organization of Zeon |
| PACK | Prefabricated Animalistic Cybernetic Killer |
| PAKW | Partition Against Khan Wall |
| PATA | Planetary Asian Tourism Association |
| PAW | Post-Apocalyptic World |
| PB | Photon Blast |
| PBC | Pitch Black Crew |
| PBM | Partial Body Morph |
| PCL | Planetary Conquest League |
| PCP | Planetary Council Protectorate |
| PCS | Pretty Complicated System |
| PCS | Projected Coordinate System |