English abbreviations from o to o8
- O (Oberst||Observer||Obstacle||Octal||Officer||Official||Oh||Operational||Operator||Oprah (magazine)||Outstanding|| Oxygen)
- O. (Hora ("Hour"); Obiit ("Died"))
- O/B (Outboard)
- O&C (Operation and Checkout)
- O/C (Observer/Collector)
- O&G (Oil and Gas)
- O&I (Operations and Intelligence)
- O+I (Outings and Innings)
- O&M (Operations and Maintenance)
- O&O (Operational and Organizational)
- O&OP (Operational and Organizational Plan)
- O&S (Operations and Support)
- O/S (Operations and Support life cycle phase)
- O1 (Officer grade: Ensign or 2nd Lieutenant)
- O10 (Officer grade: Admiral or General)
- O11 (Officer Grade: Fleet Admiral Or General of the Army)
- O2 (Object Oriented)
- O2I (Object-Oriented Interface)
- O3 (Ozone)
- O3O (O3o)
- O4 (Officer grade: Captain or Colonel)
- O5 (Officer grade: Commander or Lieutenant Colonel)
- O6 (Officer grade: Captain or Colonel)
- O7 (Officer grade: Commodore, Rear Admiral (Lower Half), or Brigadier General)
- O8 (Officer grade: Rear Admiral (Upper Half), or Major General)
