English abbreviations from opus to or-s
- OPUS (Optimising Public Understanding of Science)
- OPV (Observation Post Vehicle)
- OPW (Orthogonalized Plane Wave)
- OPWSA (Ontario Provincial Women's Softball Association)
- OPX (Open Philanthropy Exchange)
- OPZONE (Operation Zone)
- OQ (Order Quantity, in inventory management; the quantity of new items to be ordered. Often expressed as a part of OP/OQ (when quantity OP is reached, order OQ new items))
- OQA (Office of Quality Assurance)
- OQB (Opera Quarter Bar (London))
- OQE (Organization for Quality Education)
- OQF (Ordnance Quick Firing)
- OQG (Output Queue Grant)
- OQH (Online Quiz Hell)
- OQLF (Office Québécois de la Langue Française)
- OQM (Oxfordshire Quality Musclebuilding)
- OQN (Brandywine Airport)
- OQR (Office of Quality Review)
- OQS (Occupied Quantum State)
- OQT (Officer Qualification Testing)
- OQZ (Operational Quality: Zilch)
- OR (Operating room)
- Or. (Oratio ("Prayer" Breviary))
- OR(s) (Odds ratio(s))
