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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