| Abbreviation | Definition |
|---|---|
| ON | Order Now |
| ONC | Office of the National Coordinator |
| ONCO | Or Nearest Cash Offer |
| ONE | Open Network Of Enterprises |
| ONO | Or Near Offer |
| ONO | Or Nearest Offer |
| OO | Order Online |
| OO | Outer Office |
| OOB | Open Order Book |
| OOB | Opening Of Business |
| OOBE | Out Of Box Experience |
| OOCL | Object-Oriented Change and Learning |
| OODA | Observe, Orient, Decide, Act |
| OOF | Ouf Of Facility |
| OOF | Out Of the Office |
| OOH | Out Of Hours |
| OOH | Out-Of-Home advertising |
| OOK | Open Office Krapola |
| OOO | Obligatory Other Option |
| OoO | Out Of Office |