sort by Rank | Alpha
| Possible Meanings | Rank |
|---|
| Opening All Options | *** |
| Optical Astronomy Observatories | *** |
| Okayama Astrophysical Observatory | *** |
| Opticians Association of Oregon | *** |
| Orbiting Astronomical Observatories | *** |
| Online Account Opening | *** |
| Operation of Oil | *** |
| operation and after operative | ** |
| Oklahoma Academy of Ophthalmology | ** |
| Other Authorised Operators | ** |
| OCEAN ACOUSTIC OBSERVATORY | ** |
| Okayama Astronomical Observatory | ** |
| Office of Academic Opportunities | ** |
| Of Aircraft Operations | ** |
| Office of the Associate | * |
| Options Advisory Office | * |
| Orbital Astronomical Observatory | * |
| Online Activism Organization | * |
| Online Activism Organizations | * |
| Operator And Owners | * |
| Oulun Ammattikorkeak Oulu | * |
| Oyston Associates in Orillia | * |