| ... (A) | Captain, Adrmiral, etc. (A). Officer in charge of aircraft carriers. For example, Vice-Admiral (A) is the officer commanding all carriers in that command.
(Also seen as AC.) |
| (act) | Acting |
| ACOS | Admiral Commanding Orkneys and Shetlands |
| AP A/P | Auxiliary Patrol |
| A.R.A.N.Z. | Archives and Records Association of New Zealand |
| A/S | Anti-Submarine |
| BNS | Belgian Naval Ship |
| B.C. | British Columbia (Canada) |
| C/F | Coastal Forces |
| Com-i-C | Commodore-in-Charge |
| Capt-i-C | Captain-in-Charge |
| C-in-C
CiC |
Commander-in-Chief |
| (CS. ...) | Officer in command of a cruiser squadron. For example, Rear-Admiral (CS.1) is the flag officer commanding the 1st Cruiser Squadron. |
| (CSK) | Chief Store Keeper |
| (D) | Captain, Rear-Admiral, etc. (D). Officer in charge of destroyers. For example, Rear-Admiral (D) is the officer commanding all destroyers in that command. |
| (D. ...) | Officer in command of a destroyer division. For example, Captain (D.3) is the officer commanding the 3rd Destroyer Division. |
| (DF. ...) | Officer in command of a destroyer flotilla. For example, Captain (DF.6) is the officer commanding the 6th Destroyer Flotilla. |
| DNO | District Naval Officer |
| (E) | Engineer |
| (emgcy) | Emergency |
| Engr | Engineer |
| (F) | Flag |
| (FF) | Fleet or Flotilla Flag |
| FAA | Fleet Air Arm (Naval Aviation) |
| FO | Flag Officer |
| FOCRIN | Flag Officer Commanding, Royal Indian Navy |
| FOIC | Flag-Officer-in-Charge |
| FN | French Naval Ship |
| HMAS | His Majesty's Australian Ship |
| HMCS | His Majesty's Canadian Ship |
| HMIS | His Majesty's Indian Ship |
| HMS | His Majesty's Ship |
| HMNZS | His Majesty's New Zealand Ship |
| (hon) | honourary |
| HrMs | Royal Dutch Navy (Harer Majesteits) |
| KNM | Royal Norwegian Navy (Kongelig Norske Marine) |
| LCOCU | Landing Craft Obstacle Clearance* Unit (* also seen as Obstruction Clearing) |
| LL | Double Longitudinal. Equipment for sweeping of magnetic mines |
| M/S | Minesweeper
Motor Ship |
| (M/S) | Commander, Captain, etc. (M/S). Officer in charge of all mine sweepers in that command. (Also seen as MS.) |
| (N) | Naval |
| NL | Netherlands |
| N.S. | Nova Scotia (Canada) |
| NOIC | Naval Officer-in-Charge |
| N.T. | Northern Territory (Australia) |
| N.S.W. | New South Wales (Australia) |
| OIC | Officer-in-Charge |
| Ont. | Ontario (Canada) |
| ORP | Ship or Officer of the Polish Navy (Okret Rzeczypospolitej Polskiej) |
| Payr | Paymaster |
| Qld. | Queensland (Australia) |
| RAN | Royal Australian Navy |
| RCN | Royal Canadian Navy |
| (ret)
(retd) |
retired |
| RFA | Royal Fleet Auxiliary (vessels owned by the Admiralty, with Merchant Navy (i.e., civilian) crews under naval discipline, augmented with Royal Navy personnel) |
| RHN | Royal Hellenic Navy (Greece) |
| RIN | Royal Indian Navy |
| RM | Royal Marines |
| RMS | Royal Mail Ship. Seagoing vessels that carry mail under contract to the British Royal Mail. |
| RN | Royal Navy |
| RNethN RNLN |
Royal Netherlands Navy |
| RNN | Royal Norwegian Navy |
| RNO | Resident Naval Officer |
| RNR | Royal Navy Reserve |
| RNTE | Royal Navy Training Establishment |
| RNVR | Royal Navy Volunteer Reserve |
| RNVSR | Royal Navy Volunteer Supplementary Reserve |
| RNZN | Royal New Zealand Navy |
| (S) | Commander, Captain, etc. (S). Officer commanding all submarines in that command. (Also seen as S/m.) |
| (S. ...) | Officer in command of a submarine flotilla. For example, Captain (S.6) is the officer commanding the 6th Submarine Flotilla. (Also seen as S/m.) |
| S.A. | South Australia (Australia) |
| SATS | South African Training Ship |
| SOAP | Senior Officer Auxiliary Patrol |
| SO | Senior Officer |
| SNO | Senior Naval Officer |
| SOE | Special Operations Executive |
| SOMBB | Senior Officer Mobile Balloon Barrage |
| S/S | Sailing Ship (mercantile vessel) |
| Surg | Surgeon |
| UK | United Kingdom |
| Tas. | Tasmania (Australia) |
| TBR | Torpedo Bomber Reconnaissance |
| Ty | Temporary |
| Vic. | Victoria (Australia) |
| W.A. | Western Australia (Australia) |
| WO | Warrent Officer. (British: Senior Non-Commissioned Officer; US: Warrant Officer) |
| WRNVR | Women's Royal Navy Volunteer Reserve |
| W/T | Wireless/Telegraphy (radio) |