sort by Rank | Alpha
| Possible Meanings | Rank |
| Ovarian Cancer Prognostic Profile | ** |
| Ocean County Phone Punx | ** |
| Oak Creek Power Plant | ** |
| Orkney Community Planning Partnership | ** |
| Other Chemical Physical Properties | ** |
| Ontario Crop Producers and Processors | * |
| One Category per Participant Plan | * |
| Oakland Community Pools Project | * |
| Organic Certified Producers and Processors | * |