MILITARY ABBREVIATIONS AND TERMINOLOGY
| visits since 28 February 2001 |
| A | Acting or Assistant |
| AA | Anti-aircraft |
| AA&QMG | Assistant Adjutant & Quartermaster-General |
| AADC | Anti-aircraft Defence Command |
| AACC | Australian Army Catering Corps |
| AACS | Australian Army Canteen Service |
| AACS | Army Airways Communications System |
| AACU | Anti-Aircraft Co-operation Unit |
| AAF | Allied Air Forces |
| AAG | Assistant Adjutant-General |
| AAL | Australian Air League |
| AALU | Australian Air Liaison Unit |
| AAMC | Australian Army Medical Corps |
| AAMWS | Australian Army Medical Women's Service |
| AANS | Australian Army Nursing Service |
| AAOC | Australian Army Ordnance Corps |
| AASL | Anti-aircraft Searchlight |
| AAU | Air Ambulance Unit |
| ABDA | American-British-Dutch-Australian |
| ABDACOM | American British Dutch and Australian Command |
| ABO | Air Board Order |
| A/C | Aircraft |
| AC | Aircraftman |
| ACAUST | Air Commander Australia |
| ACF | Australian Comforts Fund |
| ACH | Area Combined Headquarters |
| ACH | Australian Camp Hospital |
| ACNB | Australian Commonwealth Naval Board |
| ACNS | Assistant Chief of Naval Staff |
| ACS | Airfield Construction Squadron |
| ACSEA | Air Command, South-East Asia |
| Act | Acting |
| ACW | Aircraftwoman |
| AD | Aircraft Depot |
| ADC | Aide-de-Camp |
| ADF | Australian Defence Force |
| ADGMS | Assistant Director-General Medical Services |
| ADHQ | Air Defence Headquarters |
| Adm | Admiral |
| Admin | Administration |
| Adml | Admiral |
| ADMS | Assistant Director Medical Services |
| ADOS | Assistant Director Ordnance Services |
| ADS | Advanced Dressing Station |
| ADST | Assistant Director of Supply and Transport |
| ADS&T | Assistant Director of Stores and Transport |
| Adv | Advanced |
| Adv LHQ | Advanced Land Headquarters |
| AEME | Australian Electrical and Mechanical Engineers |
| AEW&C | Airborne Early Warning and Control |
| AFC | Australian Flying Corps or Air Force Cross |
| AFA | Air Force Association |
| AFCA | Australian Flying Corps Association |
| AFHQ | Air Force Headquarters |
| AFO | Admiralty Fleet Order |
| AFO | Air Force Orders |
| AFO | Air Fitter, Ordnance |
| AFPO | Armed Forces Post Office |
| AFTS | Applied Flying Training School |
| AFTU | Air Fighter Training Unit |
| AG | Adjutant-General |
| AG | Air Gunner |
| AGH | Australian General Hospital |
| AGRS | American Graves Registration Service (US Army) |
| AGS | Allied Geographic Section |
| AHQ | Air Headquarters |
| AIB | Allied Intelligence Bureau |
| AIC | Australian Instructional Corps |
| AIF | Australian Imperial Forces |
| Air Cmdre | Air Commodore |
| AIS | Aviation Instructional Staff |
| ALC | Australian Landing Craft |
| ALO | Air Liaison Officer |
| ALUSNA | United States Naval Attache |
| AMC | Armed Merchant Cruiser |
| AMCROSS | American Red Cross |
| AMF | Australian Military Forces |
| AMOE | Air Member for Organisation and Equipment |
| AMP | Air Member for Personnel |
| AMS | Air Member for Supply or Australian Minesweepers |
| AMSE | Air Member for Supply and Equipment |
| AN&MEF | Australian Naval and Military Expeditionary Force |
| ANCW | Australian National Council of Women |
| ANGAU | Australian New Guinea Administrative Unit |
| ANLO | Australian Naval Liaison Officer |
| ANS | Air Navigation School |
| AO | Area of Opertations |
| AOB | Advanced Operational Base |
| AOC | Air Officer Commanding |
| AOC-in-C | Air Officer Commanding-in-Chief |
| AOP | Air Observation Post |
| AOS | Air Observers' School |
| APD | Destroyer-transport |
| APO | Army Post Office |
| APU | Aircraft Performance Unit |
| AQMG | Assistant Quartermaster General |
| ARA | Australian Regular Army |
| ARC | Aircrew Reception Centre |
| ARC | American Red Cross |
| ARCS | Australian Red Cross Society |
| ARD | Aircraft Repair Depot or Aircraft Receiving Depot |
| ARDU | Aircraft Research and Development Unit |
| Armd | Armoured |
| ARO | Admiralty Reporting Officer |
| ARP | Air Raid Precautions |
| Arty | Artillery |
| ASIR | Australian Station Intelligence Report |
| ASIS | Australian Secret Intelligence Service or Australian Station Intelligence Summary |
| ASIS | Armament Stores Issuing Ship |
| ASO | Assistant Section Officer |
| ASR | Air-Sea Rescue Flight |
| ASRF | Air-Sea Rescue Flight |
| Asst | Assistant |
| ASW | Anti-submarine Warefare |
| ASWG | Australian Special Wireless Group |
| A-Tk | Anti-tank |
| ATC | Air Training Corps |
| ATC | Air Transport Command (US) |
| ATF | Australian Task Force |
| ATIS | Allied Translator and Interpreter Section |
| AUSTCROSS | Australian Red Cross |
| AVG | American Volunteer Group |
| AVM | Air Vice-Marshall |
| AWA | Amalgamated Wireless of Australia |
| AWAS | Australian Women's Army Service |
| AWC | Advisory War Council |
| AWFC | Australian Women's Flying Club |
| AWL | Absent without Leave |
| AWLA | Australian Women's Land Army |
| AWM | Australian War Memorial |
| BAGS | Bombing and Air Gunnery School |
| Bataan | Codeword for Lennons Hotel in Brisbane |
| BBCAU | British Borneo Civil Affairs Unit |
| BCATP | British Commonwealth Air Training Plan (EATS Canada) |
| BCOF | British Commonwealth Occupation Force |
| Bde | Brigade |
| Bdr | Bombadier |
| BEF | British Expeditionary Force |
| BFTS | Basic Flying Training School |
| BGGS | Brigadier-General, General Staff |
| BGS | Brigadier, General Staff |
| BHQ | Battery Headquarters |
| BM | Brigade Major |
| Bn | Battalion |
| BOQ | Batchelors' Officers Quarters |
| BOR | Battery Operations Room |
| BOWO | Brigade Ordnance Warrant Officer |
| BPSO | Base Personnel Staff Office |
| Brig | Brigadier |
| BrigGen | Brigadier General |
| BSIPDF | British Solomon Islands Protectorate Defence Force |
| Bty | Battery |
| BTU | Base Torpedo Unit |
| BuDocks | Bureau of Yards and Docks (US Navy) |
| BuPers | Bureau of Naval Personnel (US Navy) |
| CA (AA) | Coast Artillery (Anti-aircraft) |
| CAC | Commonwealth Aircraft Corporation |
| CAF | Citizen Air Force or Chief of Air Force |
| CAM | Chief Air Marshall |
| Capt | Captain |
| CARU | Control and Reporting Unit |
| CAS | Chief of Air Staff |
| CASAC | Chief of the Air Staff Advisory Committee |
| CASC | Commander, Army Service Corps |
| CATF | China Air Task Force |
| Cav | Cavalry |
| CB or CBB | Central Bureau or Central Bureau Brisbane |
| CCRA | Commander, Corps Royal Artillery |
| CCS | Combined Chiefs of Staff or Casualty Clearing Station |
| CCS | Casualty Clearing Station |
| Cd | Command |
| CDF | Chief of the Defence Force |
| CDFS | Chief of the Defence Force Staff |
| CDH | Combined Defence Headquarters |
| CDL | Civil Defence Legion (Tasmania) |
| Cdo | Commando |
| CE | Controller Of Equipment (RAAF) |
| Cdr | Commander |
| CE | Chief Engineer |
| CEO | Chief Equipment Officer |
| CFD | Commander of Fixed Defences |
| CFI | Chief Flying Instructor |
| CFS | Central Flying School |
| CGCF | Commonwealth Government Clothing Factory |
| CGI | Chief Ground Instructor or Chief Gunnery Instructor |
| CGM | Conspicuous Gallantry Medal |
| CGS | Chief of the General Staff |
| CHQ | Company Headquarters |
| CI | Chief Instructor |
| CIB | Commonwealth Investigation Branch |
| CIB | Combat Infantry Badge |
| CIGS | Chief of the Imperial General Staff |
| C-in-C | Commander-in-Chief |
| CINC | Commander-in-Chief (UK) |
| CIU | Communications Intelligence Unit or Combat Intelligence Unit |
| CMF | Citizen Military Forces |
| CNF | Commonwealth Naval Forces |
| CNS | Chief of the Naval Staff |
| CO | Commanding Officer |
| COC | Commander of Command |
| COIC | Combined Operations and Intelligence Centre |
| Col | Colonel or Column |
| Col GS | Colonel, General Staff |
| COMAIRSOLS | Command Air Solomons |
| ComAirSoPac | Commander Aircraft South Pacific |
| ComAmphForSoPac | Commander, Amphibious Forces, South Australia |
| COMAST | Commander Australian Theatre |
| Comd | Commanded, Command or Commander |
| Comdt | Commandant |
| Comfis | Combined Field Intelligence Service (later NEA) |
| COMFLOT | Commodore Flotillas |
| COMGENSOPAC | Commanding General, South Pacific |
| COMINCH | Commander in Chief (US) |
| Commn | Communication |
| ComSoPac | Commander, South Pacific (USN) |
| COOP | Craft of Opportunity |
| COR | Company Operations Room |
| COSC | Chiefs of Staff Committee |
| Coy | Company |
| Cpl | Corporal |
| CRA | Commander, Royal Artillery (of a division) |
| CRE | Commander, Royal Engineers (of a Division) |
| CS | Chief of Staff |
| CSDIC | Combined Services Detailed Interrogation Centre |
| CSG | Combat Support Group |
| CSM | Company Sergeant Major |
| CSO | Chief Signals Officer |
| CSS | Commonwealth Security Service |
| CTF | Commander. Task Force |
| CU | Communications Unit |
| CWR | Central War Room |
| CRU | Chemical Research Unit |
| CWA | Country Women's Association |
| CWWW | Council for Women in War Work |
| CZM | The Commander in Chief of the Netherlands East Indies Naval Forces |
| DA & QMG | Deputy Adjutant and Quarter Master General |
| DAA & QMG | Deputy Assistant Adjutant and Quarter Master General |
| DAAI | Director of Allied Air Intelligence |
| DADMS | Deputy Assistant Director Medical Services |
| DADOS | Deputy Assistant Director Ordinance Services |
| DAOC | Deputy Air Officer Commanding |
| DAOC-in-C | Deputy Air Officer Commanding-in-Chief |
| DAP | Department of Aircraft Production |
| DAPM | Deputy Assistant Provost Marshall |
| DAQMG | Deputy Assistant Quartermaster-General |
| DAT | Directorate of Air Transport |
| DC | Detachment Commander |
| DCAS | Deputy Chief of the Air Staff |
| DCGS | Deputy Chief of General Staff |
| DCNS | Deputy Chief of the Naval Staff |
| DDL | Light Destroyer |
| DDME | Deputy Director Mechanical Engineering |
| DDMI | Deputy Director of Military Intelligence |
| DDMS | Deputy Director Medical Services |
| DDMT | Deputy Director Military Training |
| DDST | Deputy Director Supply and Transport |
| DEMS | Defensively Equipped Merchant Ships (or Shipping) |
| DF | Direction Finding |
| DFC | Distinguished Flying Cross |
| DGAMS | Director-General Australian Medical Services |
| DGMS | Director-General Medical Services |
| DGS | Director-General of Security |
| DGSP | Director-General of Supply and Production |
| Div | Division |
| DMI | Director of Military Intelligence |
| DMO & I | Director of Military Operations and Intelligence |
| DMS | Director Medical Services |
| DMT | Driver Motor Transport |
| DMT | Director of Military Training |
| DNI | Director of Naval Intelligence |
| DNO | District Naval Officer |
| DO | Demi-official (letter) |
| D of O | Director/Directorate of Organisation |
| DR | Director/Directorate of Recruiting |
| DR or Don-R | Motorcycle Dispatch Rider |
| DR Navigation | Deduced Reckoning navigation or colloquially Dead Reckoning |
| D. Sigs | Director of Signals |
| DSIO | Deputy Supervising Intelligence Officer |
| DSO | Distinguished Service Order |
| DT | Director/Directorate of Training |
| DTS | Director of Technical Services |
| D. WAAAF | Director of WAAAF |
| DUKW | An amphibious craft manufactured by Detroit United Keith Works |
| DWB | Director of Works and Buildings |
| EATS | Empire Air Training Scheme |
| EBSR | Engineer Boat and Shore Regiment |
| Ech | Echelon |
| ECHO | Shipping Designator for freight to Base Section 7, Sydney, N.S.W. |
| ED | Embarkation Depot |
| EFTS | Elementary Flying Training School |
| EL | Electric Light |
| Engrs | Engineers |
| EO | Equipment Officer or Engineer Officer |
| EPIP Tent | European Privates Indian Pattern tent |
| Eqpt | Equipment |
| ERP | Enemy Raid Precautions (Canberra) |
| ESB | Engineer Special Brigade |
| ETO | European Theatre of Operation |
| FA | Field Artillery |
| FAA | Fleet Air Arm |
| FAC | Forward Air Controller |
| FAW | Fleet Air Wing (US Navy) - previously know as Patrol Wing |
| FBRD | Flying-boat Repair Depot |
| FCS | Fraser (Island) Commando School (in Queensland) |
| Fd | Field |
| Fd Amb | Field Ambulance |
| FDL | Forward Defended Locality |
| FEAF | Far East Air Forces |
| FEB | Far Eastern Bureau (MEW/SOE) (psychological warfare) |
| FECB | Far East Combined Bureau (cryptanalysis) |
| FELO | Far Eastern Liaison Office |
| FFCF | Fighting Forces Comforts Fund |
| FIS | Foreign Intelligence Section (Canada) |
| F-Lt | Flight Lieutenant |
| FM | Finance Member or Field Marshall |
| F-O or F/O | Flying Officer |
| FOCAS | Flag Officer Commanding the Australian Squadron |
| FOD | Follow-on Destroyer |
| FOD | Forward Ordnance Depot |
| FOO | Forward Observation Officer |
| FPO | Fleet Post Office |
| FRUMEL | Fleet Radio Unit Melbourne |
| FRUPac | Fleet Radio Unit, Pacific |
| FS | Fighter Sector or Field Security |
| F-Sgt | Flight Sergeant |
| FSHQ | Fighter Sector Headquarters |
| FTS | Flying Training School |
| G-2 | Intelligence Staff of a US Headquarters |
| G-3 | Operations staff of a US Headquarters |
| GC&CS | Government Code and Cypher School (cryptology, UK) |
| GCC | Ground Control Centre |
| GCHQ | Government Communications Headquarters (UK) |
| GD | General Duties |
| GDD | General Details Depot |
| Gen | General |
| GHQ | General Headquarters |
| Gnr | Gunner |
| GOC | General Officer Commanding |
| Gp | Group |
| Gp Capt | Group Captain |
| GR | General Reconnaissance |
| GRS | General Reconnaissance School |
| GS | General Staff |
| GSO | General Staff Officer |
| GSO1 | General Staff Officer, Grade 1 |
| G Staff | Operations Staff |
| G Time | Golf Time which equals GMT plus 7 hours |
| H | Western Australian Time, 8 hrs ahead of GMT |
| HBG | Heavy Bombardment Group |
| HE | High Explosive |
| HEDRON | Headquarters Squadron (US Navy) |
| HMA | His Majesty's Australian |
| HMAS | His Majesty's Australian Ship |
| HMCS | His Majesty's Canadian Ship |
| HMS | His Majesty's Ship |
| HMNZS | His Majesty's New Zealand Ship |
| HMT | His Majesty's Transport |
| HO | Hostilities only |
| HQ | Headquarters |
| H Time | Hotel Time which equals GMT plus 8 hours |
| IASD | Inter-Allied Services Department |
| i/c | In command |
| IFF | Identification Friend or Foe |
| IG | Inspector-General |
| IJN | Imperial Japanese Navy |
| ILO | Intelligence Liaison Officer |
| IMAC | First Marine Amphibious Corps |
| Indep | Independent |
| Inf | Infantry |
| Inf Bde | Infantry Brigade |
| Instr | Instructor |
| Int | Intelligence |
| Intell | Intelligence |
| IO | Intelligence Officer |
| ISD | Inter-Allied Services Department |
| ITS | Initial Training School |
| JCS | Joint Chiefs of Staff |
| JICPOA | Joint Intelligence, Central Pacific Ocean Area |
| K Time | Kilo Time which equals Eastern Australian Standard Time which is equal to GMT plus 10 hrs |
| LARC | Lighter Amphibious Resupply Cargo vessel |
| LAA | Light Anti-aircraft |
| LAC | Leading Aircraftman |
| Landops | Advanced Land Headquarters |
| LAC | Leading Aircraftsman |
| LASU | Local Air Supply Unit |
| LCH | Landing Craft, Heavy |
| LCI | Landing Craft, Infantry |
| LCM | Landing Craft, Mechanised or Landing Craft Motorised |
| L-Cpl | Lance-Corporal |
| LCT | Landing Craft, Tank |
| LCV | Landing Craft, Vehicle or Landing Craft Vessel |
| LCVP | Landing Craft, Vehicle, Personnel |
| LEFT | Shipping Designator for Freight to Base Section 3, Brisbane, Queensland |
| LHQ | Land Headquarters or Allied Land Forces Headquarters |
| LMG | Light Machine Gun |
| LMS | Lugger Maintenance Section (Darwin) |
| LNS | League of National Security |
| LO | Liaison Office or Liaison Officer |
| L of C | Lines of Communication |
| LRPG | Long-Range Penetration Group |
| LSI | Landing Ship, Infantry |
| LSO | Legal Staff Officer |
| LST | Landing Ship, Tanks |
| Lt | Lieutenant or Light |
| Lt Cdr | Lieutenant-Commander |
| Lt-Col | Lieutenant-Colonel |
| Lt-Gen | Lieutenant-General |
| LTD | Leave and Transit Depot |
| LW/AW | Light Weight Air Warning (Radar station developed by AWA) |
| MAC | Motor Ambulance Convoy |
| Maj | Major |
| Maj-Gen | Major-General |
| MAZE | Shipping Designator for Freight to Base Section 4, Melbourne, Victoria |
| MBDS | Main Bench Dressing Station |
| MC | Military Cross |
| MD | Military District |
| MDS | Main Dressing Station |
| ME | Middle East |
| MEIC | Middle East Intelligence Centre |
| MEW | Ministry of Economic Warfare (SOE) |
| MFCU | Mobile Fighter Control Unit |
| MG | Machine-Gun |
| MGGS | Major General, General Staff |
| MGO | Master General of the Ordnance |
| MGRA | Major-General, Royal Artillery |
| MHQ | Maritime Headquarters |
| MI-5 | Military Intelligence 5 (UK, Internal Security) |
| MI-6 | Military Intelligence 6 (UK, External, see SIS) |
| Mil | Military |
| MIS | Military Intelligence Service |
| MISLS | Military Intelligence Service Language School |
| MIS-X | Military Intelligence Service - 'X' Section (US) |
| MMG | Medium Machine-gun |
| MO | Medical Officer |
| MOI | Ministry of Information |
| MRO | Military Reporting Officer |
| MTF | Mobile Task Force |
| Mtn | Mountain |
| MU | Maintenance Unit |
| MUR | Melbourne University Rifles |
| MV | Motor Vessel |
| NAOU | North Australia Observer Unit or Nackeroos |
| NAP | Naval Auxiliary Patrol |
| NATS | Naval Air Transport Service |
| NCO | Non-Commissioned Officer |
| NEA | North-East Area |
| NEAHQ | North East Area Headquarters |
| NEFIS | Netherlands East Indies Forces Intelligence Forces |
| NEI | Netherlands East Indies |
| NEI-AF | Netherlands East Indies Air Force |
| NEFIS III | Netherlands Forces Intelligence Section, Division III |
| NES | National Emergency Services (New South Wales) |
| NG | New Guinea |
| NGAWW | New Guinea Air Warning Wireless (Independent) Company |
| NGF | New Guinea Force |
| NGIB | New Guinea Infantry Battalion |
| NGVR | New Guinea Volunteer Rifles |
| NID | Naval Intelligence Division (formerly Naval Intelligence Department) |
| NIO | Naval Intelligence Officer |
| NLO | Naval Liaison Officer |
| NOIC | Naval Officer in Charge |
| Norforce | Northern Territory Force or NT Force |
| NT | Northern Territory |
| NT Force | Northern Territory Force or Norforce |
| NTSRU | Northern Territory Special Reconnaissance Unit |
| NYDN | Not yet diagnosed neurosis |
| NZ & A | New Zealand and Australian Division |
| NZNB | New Zealand Naval Board |
| OB | Operational Base |
| OBE | Officer of the Order of the British Empire |
| OBU | Operational Base Unit |
| OC | Officer Commanding |
| OC Med | Officer in charge, medical |
| OC Surg | Officer in charge, surgical |
| ODF | Operational Deployment Force |
| Offr | Officer |
| OG | Operational Group |
| OHQ | Overseas Headquarters |
| OIC | Officer in Charge |
| OM/P | Oriental Mission/Propaganda (SOE Malaya) |
| ONI | Officer of Naval Intelligence (US) |
| OOB | Order of Battle |
| OP | Observation Post |
| Ops | Operations |
| ORs | Other Ranks (other than officers) |
| Orgn | Organisation |
| OSMG | Owen sub-machine-gun |
| OSS | Office of Strategic Services |
| OTS | Officer's Training School |
| OTU | Operational Training Unit |
| PAA | Pan American Airways |
| PAF | Permanent Air Force |
| PATSU | Patrol Service Units (US Navy) |
| PatWing | Patrol Wing (US Navy) |
| PDRC | Personnel Dispatch and Reception Centre |
| PIB | Papuan Infantry Battalion |
| PIR | Pacific Islands Regiment |
| Pk | Park |
| PMF | Permanent Military Force |
| PNF | Permanent Naval Forces |
| PNGDF | Papua New Guinea Defence Force |
| Pnr | Pioneer |
| P-O | Pilot Officer |
| POR | Personnel Occurrence Reports |
| POW | Prisoners of War |
| PRC | Personnel Reception Centre |
| PRO | Public Relations Officer |
| PRS | Philippines Regional Section |
| PRU | Photographic Reconnaissance Unit |
| p.s.c | Passed Staff Course |
| PT | Patrol Torpedo (boat) |
| PTE | Private |
| PUO | Pyrexia of unknown origin |
| PWC | Political Warfare Committee |
| PWCC | Prisoner of War Control Center |
| QANTAS | Queensland and Northern Territory Aerial Services |
| QM | Quartermaster |
| QMG | Quartermaster General |
| Q Staff | Quartermaster Staff |
| RAA | Royal Australian Artillery |
| RAAF | Royal Australian Air Force |
| RAAFCF | RAAF Comforts Fund |
| RAAFLO | Royal Australian Air Force London Office |
| RAAFNS | Royal Australian Air Force Nursing Service |
| RADAR | Radio Detection and Ranging |
| RAE | Royal Australian Engineers |
| RAF | Royal Air Force |
| RAGA | Royal Australian Garrison Artillery |
| RAAMC | Royal Australian Army Medical Corps |
| RAANC | Royal Australian Army Nursing Corps |
| RACAS | Rear Admiral commanding the Australian Squadron |
| RANC | Royal Australian Naval College |
| RAN | Royal Australian Navy |
| RANC | Royal Australian Naval College |
| RANNS | Royal Australian Navy Nursing Service |
| RANR | Royal Australian Navy Reserve |
| RANVR | Royal Australian Naval Volunteer Reserve |
| RAP | Regimental aid post |
| RAPWI | Recovered Allied Prisoners of War and Internees |
| RAR | Royal Australian Regiment |
| RCAF | Royal Canadian Air Force |
| RCN | Royal Canadian Navy |
| RDF | Radio Direction Finding |
| RE | Royal Engineers |
| Recce | Reconnaissance |
| Regt | Regiment |
| RFA | Royal Field Artillery |
| RFC | Royal Flying Corps |
| RIAF | Royal Indian Air Force |
| RMC | Royal Military College, Duntroon |
| RMO | Regimental Medical Officer |
| RN | Royal Navy |
| RNAS | Royal Naval Air Service |
| RNC | Royal Naval College |
| RNZAF | Royal New Zealand Air Force |
| RNZN | Royal New Zealand Navy |
| RO | Routine Order |
| ROO | Rail Ordnance Officer |
| RSM | Regimental Sergeant Major |
| RSU | Repair and Salvage Unit |
| R/T or R-T | Radio Telephony - voice transmissions |
| RTO | Rail Transport Officer |
| SAO | Senior Administrative Officer |
| SAP | Semi armour-piercing |
| SAS | Special Air Service |
| SASO | Senior Air Staff Officer |
| SCO | Searchlight Control Officer |
| SEA | South-East Asia |
| SEAC | South-East Asia Command |
| Sec | Section or Secretary |
| SEATIC | South East Asia Translation and Interrogation Center |
| SFTS | Service Flying Training School |
| Sgt | Sergeant |
| SHAEF | Supreme Headquarters, Allied Expeditionary Force |
| Sh. D. | Shore Defence |
| SHQ | Station Headquarters or Section Headquarters |
| SI | Special Intelligence (cryptanalysis) |
| SIA | Special Intelligence Australia |
| SIB | Special Intelligence Bureau (Melbourne, Wireless Intelligence) |
| Sig | Signalman |
| Sigint | Signals Intelligence |
| Sigs | Signals |
| SIONEA | Supervising Intelligence Officer, North East Area |
| SIS | Secret Intelligence Service or Signals Intelligence Service (US) |
| SISO | Senior Intelligence Staff Officer |
| SLC | Searchlight Control or Radar (also known as "Elsie") |
| SLU | Secret Liaison Unit or Special Liaison Unit (British Ultra) |
| SMO | Senior Medical Officer |
| SMSO | Senior Maintenance Staff Officer |
| SNLF | Special Naval Landing Force (Japanese) |
| SNO | Senior Naval Officer |
| SNO | Senior Navigation Officer |
| SO | Staff Officer |
| SOA | Special Operations Australia |
| SOE | Special Operations Executive |
| SO(I) | Staff Officer (Intelligence) |
| SOPAC | South Pacific (Command) |
| SORE | Staff Officer, Royal Engineers |
| SPC | State Publicity Censor |
| Spr |