| Abbreviation | Definition |
|---|---|
| NYOG | New York Otolaryngology Group |
| NYSAPLS | New York State Association of Professional Land Surveyors |
| NYSIA | New York Society of Independent Accountants |
| NYSSPE | New York State Society of Professional Engineers |
| NZCPA | New Zealand Canoe Polo Association |
| NZCPA | New Zealand Cricket Players Association |
| OAA | Obstetric Anaesthetists' Association |
| OAA | Ontario Association of Architects |
| OAA | Opticians Association of America |
| OAA | Oriental Astronomical Association |
| OAB | Ohio Association of Broadcasters |
| OAB | Oklahoma Accountancy Board |
| OAB | Oklahoma Association of Broadcasters |
| OAB | Oregon Association of Broadcasters |
| OAB | Ostomy Association of Boston |
| OAC | Ontario Aerospace Council |
| OACES | Ohio Association For Counselor Education Supervision |
| OACES | Ohio Association Of Counselor Education And Supervision |
| OACES | Oregon Association For Counselor Education And Supervision |
| OACES | Oregon Association Of County Engineers And Surveyors |