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Military
List of Abbreviations Used in Military Service Files
- O -
| Abbreviation | Meaning |
|---|---|
| O | Observer |
| O | Qualified Naval Observer |
| O | Operations Branch of the General Staff |
| O/ | Ordinary |
| O/C | Officer Commanding |
| O/Cdt | Officer Cadet |
| O/S | Overseas |
| O/S | Ordinary Seaman |
| O/SDCCODRCOC | Overseas Detachment Canadian Camp Ordnance Depot, Royal Canadian Ordnance Corps |
| OA | Ordnance Artificer |
| OA,1c(or 2c,3c,4c,5c) | Ordnance Artificer, 1st Class (or 2nd,3rd,4th or 5th Class) |
| OAC | Ontario Agricultural College |
| OAC | Ordnance Ammunition Company |
| OAC | Ottawa Area Command |
| OACRCOC | Ordnance Ammunition Company, Royal Canadian Ordnance Corps |
| OACRO | Ottawa Area Command Routine Orders |
| OAMCU | Overseas Air Movements Control Unit |
| OAP | Observation Amphibian Plane (U.S.) |
| OARCE | Officer Administering, Royal Canadian Engineers |
| OBE | Officer of the Order of the British Empire |
| OBLI | Oxfordshire & Buckinghamshire Light Infantry |
| OBV | Ocean Boarding Vessel |
| OC | Officer Cadet |
| OC | Officer Commanding |
| OC | Officer of the Order of Canada |
| OC | Officer Commanding |
| OC | Officer's Clerk |
| OCDP | Officer Career Development Plan |
| OCdr | Ordinary Coder |
| OComm | Orders Committee |
| OCRCRCAMC | Oakville Casualty Retraining Centre, Royal Canadian army Medical Corps |
| OCRN | Officer Commanding, Royal Navy |
| OCT | Officer Cadet in Training |
| OCTP | Officer Cadet Training Plan |
| OCTP | Officer Candidate Training Plan |
| OCTU | Officers Cadet Training Unit |
| OCW | Officer-in-Charge Works |
| OD | Air Mechanic (Ordnance) |
| ODC | Ordnance Depot Company |
| ODSRCOC | Ordnance Depot Saskatoon, Royal Canadian Ordnance Corps |
| ODT | Office of Defence Transportation |
| OEO | Ordnance Engineer Office |
| Off | Office |
| OffcCdt | Officer Cadet |
| Offr | Officer |
| OGp | Orders Group |
| OGS | Officer General Specification |
| OHA | Osmali Horse Artillery |
| OHF | Occupational History Form |
| Oi/c | Officer of Charge |
| OIC | Officer in Charge |
| OIC | Osmali Irregular Cavalry |
| OINC | Officer-in-Charge |
| OinC | Order in Council |
| OItoCSGHQEA | (Ordnance) Increment to Canadian Section General Headquarters Echelon Army Group |
| OKH | Oberkommando des Heeres (Army High Command, Berlin) |
| OKW | Oberkommando der Wehrmacht (Armed Forces High Command) |
| OLP | Observation Landplane (U.S.) |
| OM | Order of Merit |
| OM | Overseas Minister |
| OMD | Ordnance Medical Department |
| OMERU | Ordnance Mechanical Engineers Reinforcement Unit |
| OMFC | Overseas Military Forces of Canada |
| OMHRCAMC | Orillia Military Hospital, Royal Canadian Army Medical Corps |
| OMHRCAMC | Ottawa Military Hospital, Royal Canadian Army Medical Corps |
| OMHRCAMC | Ozada Military Hospital, Royal Canadian Army Medical Corps |
| OMM | Officer of the Order of Military Merit |
| OMO | Ordnance Mechanical Officer |
| ON | Official Number |
| ON | United Kingdom-North America Convoy |
| ONS | United Kingdom-North America Slow Convoy |
| Ont | Ontario |
| OntR | Ontario Regiment |
| OntRgt | Ontario Regiment |
| ONUC | Organisation des Nations Unies au Congo |
| OO | Ordnance Officer |
| OO | Operation(al) Order |
| OOD | Officer of the Day |
| OofPCTintheFAAI | Office of the Paymaster Canadian Troops in the Field Allied Armies in Italy |
| OoftheI-G | Office of the Inspector-General |
| OoftheJAG | Office of the Judge Advocate General |
| OOG | Officer of the Guard |
| OOP | Officer of Patrol |
| OOPE | Officer in charge Office Practice & Equipment (Naval) |
| OOW | Officer of the Watch |
| OP | Observation Post |
| OP | Observation Point |
| op | operating |
| OPD | Other Protestant Denomination |
| OPDP | Officer Professional Development Program |
| OpEEqpt | Operator Engineering Equipment |
| OPI | Office of Primary Interest |
| OPME | Officer Professional Military Education |
| OpMME | Operator Mechanic Mobile Equipment |
| OPNAV | Chief of Naval Operations (U.S.) |
| OpRmA | Operating Room Assistant |
| Oprs | Director of Military Operations & Intelligence |
| ops | operations |
| OpSbd | Operator Switchboard |
| OpsO | Operations Officer |
| OpSSE | Operator (Special Engineering Equipment) |
| OPtlmn | Ordinary Patrolman |
| OPV | Offshore Patrol Vessel |
| OQ | Occupation Qualification |
| OR | Ontario Regiment |
| OR | Other Rank |
| OR | Oxford Rifles |
| OR | Operating Room Assistant |
| OR | Orderly |
| OR | Ontario Regiment |
| OR | Other Rank(s) |
| OR | Orderly Room |
| ORBS | Overseas Recorded Broadcasting Service |
| ORD | Ordinary Seaman |
| Ord | Ordnance |
| Org | Director of Organization |
| ORP | Polish Ship |
| ORS | Orderly Room Sergeant |
| ORS | Ottawa Routeing Summary |
| ORSE | Orderly Room Sergeant |
| OS | Officers School |
| OS | Ordinary Seaman |
| OS | Ordinary Seaman |
| OS | Officer's Steward |
| OS | Overseas |
| OS(Records) | Observation Section |
| OSAB | Officer's Selection Appraisal Board (O-1 Officers' Training Centre) |
| OSAC | Officer Selection Appraisal Centre |
| OSAIRCOC | Ordnance Stores Accounting Inspectorate, Royal Canadian Ordnance Corps |
| OSC | Ordnance Store Company |
| OSC | Ordnance Staff Corps |
| OSCRCOC | Ordnance Store Company, Royal Canadian Ordnance Corps |
| OSig | Ordinary Signalman |
| OSMSCMHQRCOC | Ordnance Services Mobilization Staff, Canadian Military Headquarters, Royal Canadian Ordnance Corps |
| OSQ | Occupation Specialty Qualification |
| OSRD | Office of Scientific Research and Development |
| OSSDRCOC | Officers Shop Supply Depot, Royal Canadian Ordnance Corps |
| OT | Occupation Transfer |
| OT | Aruba-Dakar convoy |
| OTC | Officer in Tactical Command (U.S.) |
| OTC | Officers Training Centre |
| OTC | Officer Training Corps |
| OTC | Officer Training Candidate |
| OTC"R" | Officers Training Centre "Reserve" |
| OTel | Ordinary Telegraphist |
| OTS | Officers Training School |
| OTS | Operational Training Squadron |
| OTU | Operational Training Unit(s) |
| OU | Official Use |
| OW/SCoyRCOC | Ottawa Workshop Company, Royal Canadian Ordnance Corps |
| OW/SRCEME | Ottawa Workshop, Royal Canadian Electrical and Mechanical Engineers |
| OW/SRCOC | Ordnance Workshop, Royal Canadian Ordnance Corps |
| Ox&BucksLI | Oxfordshire & Buckinghamshire Light Infantry |
| OxfYeo | Oxfordshire Yeomanry |
| OXV | Outer Examination Vessel |
