A3: early radiotelephone voice encryption system
ASF: Army Service Force
ASW: antisubmarine warfare
AT: troop convoy designation, United States to UK
B-17: four-engine heavy bomber
B-24: four-engine heavy bomber (with transport and maritime patrol variants)
BA: British Army
C-54: four-engine transport aircraft
CBO: Combined Bomber Offensive
CCS: Combined Chiefs of Staff (Allied)
CIGS: Chief of Imperial General Staff (UK)
COS: Chiefs of Staff (UK)
COSSAC: Chief of Staff to Supreme Allied Commander, an organization and an officer’s title
CVE: escort aircraft carrier
CU: convoy designation, Caribbean to Liverpool
ETOUSA: European Theater of Operations, U.S. Army
HF/DF: high frequency direction
HMS: His Majesty’s Ship
HX: convoy designation, Halifax (later New York) to Liverpool
HXS: convoy designation, Halifax (later New York) to Liverpool, slow
JCS: Joint Chiefs of Staff (U.S.)
JIC: Joint Intelligence Committee
JPC: Joint Planning Committee (UK)
JSSC: Joint Strategy Survey Committee (U.S.)
JWPC: Joint War Planning Committee (U.S.)
KMF: convoy designation, Firth of Clyde to Mediterranean
MKF: convoy designation, Mediterranean to Firth of Clyde
OKW: Oberkommando der Wehrmacht, German Supreme Command of the Armed Forces
ON: convoy designation, outbound north, Liverpool to Halifax
ONS: convoy designation, outbound north slow, Liverpool to Halifax
OPD: Operations Division (U.S. Army)
OSRD: Office of Scientific Research and Development (U.S.)
RAF: Royal Air Force
RCMP: Royal Canadian Mounted Police
RMS: Royal Mail Ship
RN: Royal Navy
S-1: code name, atomic bomb development, U.S. term equivalent to Tube Alloy
SHAEF: Supreme Headquarters Allied Expeditionary Force
TA: Tube Alloy
TU: fast troop convoy designation, British Isles to United States
USA: U.S. Army
USAAF: U.S. Army Air Force
USAT: U.S. Army Transport
USN: U.S. Navy
USS: United States Ship
USSBS: U.S. Strategic Bombing Survey
UT: fast troop convoy designation, United States to British Isles
VHF: very high frequency
VLR: very long range
WSA: War Shipping Administration