Abbreviations
| AA | Anti-Aircraft |
| AA | Army Act |
| AA & QMG | Assistant Adjutant and Quartermaster General |
| AASC | Anti-Aircraft Searchlight Company |
| AASS | Anti-Aircraft Searchlight Section |
| AB | Army Book |
| ABPO | Advanced Base Post Office |
| ACG | Assistant Chaplain General |
| ACI | Army Council Instruction |
| ACC | Army Cyclist Corps |
| AD | (or Art. Dpt) Artillery Depot |
| ADAPS | Assistant Director Army Postal Services |
| ADC | Aide de Camp |
| ADGT | Assistant Director-General of Transportation |
| ADL | Assistant Director of Labour |
| ADLR | Assistant Director of Light Railways |
| ADMS | Assistant Director Medical Services |
| ADOS | Assistant Director Ordnance Services |
| ADRT | Assistant Director Railway Traffic |
| ADS | Advanced Dressing Station |
| ADTN | Assistant Director Transportation |
| ADVS | Assistant Director Veterinary Services |
| AEC | (or A. Emp. Coy) Area Employment Company |
| AF | Army Form |
| AFA | Army Field Artillery; Australian Field Artillery |
| AG | Adjutant General |
| AGS | Army Gymnastic Staff |
| AIF | Australian Imperial Force |
| AIS | Assistant Inspector of Searchlights |
| AMFO | Assistant Military Forwarding Officer |
| AMLO | Assistant Military Landing Officer |
| AMO | Administrative Medical Officer |
| AMS | Assistant Military Secretary |
| ANZAC | Australian and New Zealand Army Corps |
| AO | Army Order |
| AOC | Army Ordnance Corps |
| AOD | Army Ordnance Department |
| AP | Armour Piercing (ammunition) |
| APC | Army Pay Corps and Assistant Principal Chaplain |
| APM | Assistant Provost Marshal |
| APO | Army Post Office |
| AQMG | Assistant Quartermaster-General |
| ARMW | Army Reserve Munition Worker |
| ARD | Alberta Reinforcement Depot |
| ARP | Ammunition Refilling Point |
| ARS | Advanced Regulating Station |
| ASC | Army Service Corps |
| ASD | Army Schools Department |
| ASO | Area Searchlight Officer |
| ASP | (or Amm. Sub. Pk) Ammunition Sub-Park |
| AT | Army Troops |
| AVC | Army Veterinary Corps |
| BAC | Brigade Ammunition Column |
| BAPO | Base Army Post Office |
| BC | Battery Commander or Base Commandant |
| BCA | Battery Commander’s Assistant |
| Bdmr | Bandmaster |
| BG | Broad Gauge (railway) |
| BGGS | Brigadier-General General Staff |
| BGRA | Brigadier-General Royal Artillery |
| BL | Breech Loading |
| BLC | Breech Loading Converted |
| BM | Brigade Major |
| BOR | British Other Rank |
| BRCS | British Red Cross Society |
| BSM | Battery Sergeant-Major |
| BWI | British West Indies Regiment |
| BWM | British War Medal |
| CB | Confinement to Barracks (punishment) and Counter-Battery |
| CBSO | Counter-Battery Staff Officer |
| CC | Confined to Camp (punishment) |
| CCCC | Cape Colony Cyclist Corps |
| CCD | Commander of Coast Defences |
| CCRA | Corps Commander Royal Artillery |
| CCS | Casualty Clearing Station |
| CDS | Corps Dressing Station |
| CE | Chief Engineer |
| CEF | Canadian Expeditionary Force |
| CEPC | Chief Engineer Port Construction |
| CF | Chaplain to the Forces |
| CFC | Canadian Forestry Commission |
| CGS | Chief of General Staff |
| CHA | Commander Heavy Artillery |
| CHDAVC | Convalescent Horse Depot Army Veterinary Corps |
| CID | Committee of Imperial Defence |
| CIGS | Chief of the Imperial General Staff |
| CLC | Chinese Labour Corps |
| CLLE | Charger-Loading Lee-Enfield rifle |
| CLLM | Charger-Loading Lee-Metford rifle |
| CLRO | Corps Light Railway Officer |
| CME | Chief Mechanical Engineer |
| CMO | Court-Martial Officer |
| CMP | Corps of Military Police |
| CO | Commanding Officer, Conscientious Objector |
| COO | Chief Ordnance Officer |
| CP | Censorship & Publicity |
| Cpl | Corporal (rank) |
| CQMS | Company Quartermaster Master Sergeant |
| CRA | Commanding Royal Artillery |
| CRCE | Chief Railway Construction Engineer |
| CRE | Commanding Royal Engineers |
| CRO | Corps Roads Officer |
| CSIC | Cadet School Infantry Company |
| CSM | Company Sergeant Major |
| CT | Communication Trench |
| CVBC | Cape Volunteer Bearer Corps |
| D of A | Director of Artillery |
| DA | Divisional Artillery |
| DAA | Director of Army Accounts |
| DAAG | Deputy Assistant Adjutant General |
| DAC | Divisional Ammunition Column |
| DACG | Deputy Assistant Chaplain General |
| DADAPS | Deputy Assistant Director Army Postal Services |
| DADGR&E | Deputy Assistant Director of Graves Registration and Enquires |
| DADGT | Deputy Assistant Director-General of Transportation |
| DADL | Deputy Assistant Director of Labour |
| DADMS | Deputy Assistant Director Medical Services |
| DADOS | Deputy Assistant Director Ordnance Services |
| DADPS | Deputy Assistant Director Postal Services |
| DAD Roads | Deputy Assistant Director of Roads |
| DAD Sigs | Deputy Assistant Director of Signals |
| DADRT | Deputy Assistant Director Railway Traffic |
| DADS | Deputy Assistant Director Supplies |
| DADT | Deputy Assistant Director Transport |
| DADW | Deputy Assistant Director of Works |
| DAG | Deputy Adjutant General |
| DAMS | Deputy Assistant Military Secretary |
| DAP | Divisional Ammunition Park |
| DAPC | Deputy Assistant Principal Chaplain |
| DAPS | Director of Army Postal Services |
| DAQMG | Deputy Assistant Quartermaster General |
| DA & QMG | Deputy Adjutant and Quartermaster General |
| DBC | Director of Barrack Construction |
| DCIGS | Deputy Chief of the Imperial General Staff |
| DCM | Distinguished Conduct Medal |
| DDAPS | Deputy Director of Army Postal Services |
| DCM | District Court-Martial |
| DDGMR | Deputy Director-General Military Railways or Movements and Railways |
| DDGT | Deputy Director-General of Transportation |
| DDIWT | Deputy Director Inland Waterway Transport |
| DDMS | Deputy Director Medical Services |
| DDOS | Deputy Director Ordnance Services |
| DDRT | Deputy Director Railway Traffic |
| DD S and T | Deputy Director Supplies and Transport |
| DD Sigs | Deputy Director of Signals |
| DDTN | Deputy Director of Transportation |
| DDVS | Deputy Director Veterinary Services |
| DDW | Deputy Director of Works |
| DEOS | Director of Equipment and Ordnance Stores |
| DFC | Distinguished Flying Cross |
| DFS | Director of Financial Services |
| DFW | Director of Fortifications and Works |
| DGAMS | Director-General, Army Medical Services |
| DGAVS | Director-General, Army Veterinary Services |
| DGNS | Director-General National Service |
| DGO | Divisional Gas Officer |
| DGTF | Director-General of the Territorial Force |
| DIL | Dangerously Ill List |
| DIWD | Director Inland Waterways and Docks |
| DIY | Derbyshire Imperial Yeomanry |
| DLR | Director of Light Railways |
| DM | Director of Mobilisation |
| DMO | Director of Military Operations |
| DMS | Director of Medical Services, also Deputy Military Secretary |
| DMT | Director of Military Training |
| DNTO | Divisional Naval Transport Officer |
| DORA | Defence of the Realm Act |
| DORE | District Office Royal Engineers |
| DOS | Director of Ordnance Services |
| DP | Drill Purpose |
| DPS | Director of Personal Services |
| DPW | Director of Prisoners of War |
| DQMG | Deputy Quartermaster-General |
| DR | Despatch Rider |
| DR | Despatch Rider |
| DRF | Depression Range-Finder |
| DRG&E | Director of Graves Registration and Enquires |
| DRLS | Despatch Rider Letter Service |
| D Rlys | Director of Railways |
| DRO | Director of Recruiting and Organisation |
| DRT | Director Railway Traffic |
| DSC | Distinguished Service Cross (a naval decoration) |
| DSD | Director of Staff Duties |
| DSM | Distinguished Service Medal (a naval decoration) |
| DSO | Distinguished Service Order |
| DSQ | Director of Supplies and Quartering |
| DTM | Director of Transport and Movements |
| DTMO | Divisional Trench Mortar Officer |
| DTN | Director of Transportation |
| DW | Director of Works |
| EBSVR | East Bengal State Volunteer Rifles |
| EEF | Egyptian Expeditionary Force |
| EFC | Expeditionary Force Canteen |
| EinC | Engineer in Chief |
| ELC | Egyptian Labour Corps |
| E&M | Electrical and Mechanical |
| EMO | Embarkation Medical Officer |
| FANY | First Aid Nursing Yeomanry |
| FAO | Forward Area Officer (Light Railways) |
| FAU | Friends Ambulance Unit |
| FGCM | Field General Court-Martial |
| FLC | Fijian Labour Contingent (later Corps) |
| FOO | Forward Observation Officer |
| FP | Field Punishment |
| FPO | Field Post Office |
| FSC | Field Survey Company |
| FSL | Field Searchlight |
| FSM | Field Service Manual |
| FSR | Field Service Regulations |
| FWD | Four Wheel Drive |
| GCM | General Court-Martial |
| GHQ | General Headquarters |
| GMP | Garrison Military Police |
| GOC | General Officer Commanding |
| GOCinC | General Officer Commanding-in-Chief |
| GRC | Graves Registration Commission |
| GRO | General Routine Order |
| GRU | Graves Registration Unit |
| GS | General Service and General Staff |
| GSO | General Staff Officer |
| GSW | Gunshot Wound |
| HA | Heavy Artillery |
| HAR | Heavy Artillery Reserve |
| HBMGC | Heavy Branch Machine Gun Corps (later Tank Corps) |
| HE | High Explosive |
| HPD | Home Postal Depot |
| HS | Home Service |
| HSC | Hospital Ship Case (medical) |
| HT | Horse Transport |
| HV | High Velocity |
| IA | Indian Army |
| IAF | Independent Air Force |
| IE | Illegal enlistment |
| IGC | Inspector-General of Communications |
| IGT | Inspector-General of Transportation |
| IHL | Imprisonment with Hard Labour |
| IO | Intelligence Officer |
| IOM | Inspector of Ordnance Machinery |
| IOR | Indian Other Rank |
| IS | Inspector of Searchlights |
| IWGC | Imperial War Graves Commission |
| IWT | Inland Water Transport |
| IW&D | Inland Waterways and Docks |
| JAG | Judge Advocate General |
| KR | King’s Regulations |
| L/C or L/Cpl | Lance Corporal |
| LEE | London Electrical Engineers |
| LO | Liaison Officer |
| LofC | Lines of Communication |
| LR | Local Reserve |
| MAC | Motor Ambulance Convoy |
| MB | Medical Board |
| MC | MIlitary Cross |
| MDS | Main Dressing Station |
| MEF | Mediterranean Expeditionary Force |
| MFD | Military Forwarding Department |
| MFO | Military Forwarding Officer |
| MFP | Military Foot Police |
| MGC | Machine Gun Corps |
| MGGS | Major General General Staff |
| MGO | Master-General of the Ordnance |
| MGRA | Major General Royal Artillery |
| MGS | Machine Gun School |
| MLO | Military Landing Officer |
| MM | Military Medal |
| MMGC | Motor Machine Gun Corps |
| MML | Manual of Military Law |
| MMP | Military Mounted Police |
| MPI | Mean Point of Impact |
| MPSC | Military Police Staff Corps |
| MS | Military Secretary |
| MSM | Meritorious Service Medal |
| MT | Mechanical Transport |
| MVC | Motor Volunteer Corps |
| MVS | Mobile Veterinary Section |
| NACB | National Army Catering Board |
| NCC | Non-Combatant Corps |
| NTO | Naval Transport Officer |
| NYD | Not Yet Diagnosed (medical term) |
| NYDN | Not Yet Diagnosed Nervous (medical term for suspected shell shock) |
| OC | Officer Commanding, Officer Cadet |
| OR | Other Rank |
| ORS | Orderly Room Sergeant |
| OTC | Officers Training Corps |
| PB | Permanent Base (medical) |
| PBI | Poor Bloody Infantry (colloquial) |
| P & BT | Physical and Bayonet Training |
| PC | Principal Chaplain (non Church of England) |
| PM | Provost Marshal |
| PNTO | Principal Naval Transport Officer |
| POW | Prisoner of War |
| PPCLI | Princess Patricia's Canadian Light Infantry |
| psc | Passed Staff College |
| Pte | Private (rank) |
| PU | Permanently Unfit (medical) |
| PUO | Pyrexia of Unknown Origin (medical term usually applied to Trench Fever) |
| QF | Quick Firing |
| QMAAC | Queen Mary’s Army Auxiliary Corps |
| QMG | Quartermaster General |
| QMS | Quartermaster Sergeant |
| Qs | Qualified for Staff |
| RAF | Royal Air Force |
| RAFA | Royal Australian Field Artillery |
| RAGA | Royal Australian Garrison Artillery |
| RAP | Regimental Aid Post |
| RCE | Railway Construction Engineer |
| RCO | Railway Control Officer |
| RDC | Royal Defence Corps |
| REPS | Royal Engineers Postal Section |
| RFA | Royal Field Artillery |
| RFC | Royal Flying Corps |
| RGA | Royal Garrison Artillery |
| RH | Railhead |
| RHA | Royal Horse Artillery, and Reserve Heavy Artillery |
| RM | Riding Master, and Royal Marines |
| RMA | Royal Marine Artillery |
| RMLC | Royal Marine Labour Corps |
| RMLI | Royal Marine Light Infantry |
| RNAS | Royal Naval Air Service |
| RND | Royal Naval Division (63 Div) |
| RO | Recruiting Officer |
| ROD | Railway Operating Division |
| ROO | Railway Ordnance Officer |
| RP | Rules of Procedure, Regimental Police, Refilling Point |
| RSM | Regimental Sergeant Major |
| RSO | Railhead Supply Officer |
| RTC | Reserve Training Centre |
| RTE | Railway Transport Establishment |
| RTO | Railway Transport Officer (later Railway Traffic Officer) |
| RTU | Returned to Unit |
| S | Service |
| SAA | Small Arms Ammunition |
| SANLC | South African Native Labour Corps |
| SC | Staff Captain |
| SCF | Senior Chaplain to the Forces |
| SD | Staff Duties |
| SGS | Surveyor-General of Supply |
| Sgt | Sergeant (rank) |
| SIW | Self-Inflicted Wound |
| Sjt | Serjeant (rank) |
| SLR | Superintendent of Light Railways |
| SMLE | Short Magazine Lee-Enfield |
| SOS | Struck off strength. Also used in usual sense (of emergency). |
| SP | Strongpoint |
| SPT | (preceding a man's number) Sportmen's Battalion Royal Fusiliers |
| SR | Special Reserve |
| SRS | Sound Ranging Section |
| SSM | Squadron Sergeant Major (cavalry) |
| STK | (preceding a man's number) Stockbroker's Battalion Royal Fusiliers |
| TAT | Temporary Ambulance Train |
| TB | Temporary Base (medical) |
| TC | Tank Corps |
| TCO | Train Conducting Officer |
| TDO | Telephone Dug-out |
| TEE | Tyne Electrical Engineers |
| TF | Territorial Force |
| TM | Trench Mortar |
| TMB | Trench Mortar Battery |
| TO | Transport Officer |
| TOS | Taken on strength |
| TR | Training Reserve |
| TRB | Training Reserve Brigade |
| TSM | Troop Sergeant Major (cavalry) |
| VAD | Voluntary Aid Detachment |
| VADGS | Voluntary Aid Detachment General Service |
| VC | Victoria Cross |
| VO | Veterinary Officer |
| VTC | Volunteer Training Corps |
| WAAC | Women’s Army Auxiliary Corps (later QMAAC) |
| WD | War Department |
| WE | War Establishment |
| WIR | West India Regiment |
| WO | War Office |
| WWCS | Walking Wounded Collecting Station |
| YOC | Young Officers Company |
| YS | Young Soldier |