BG - bomb group BGS - bombing gunnery school     BS - bomb squadron     BTU - bombing trials unit
BULLSEYE - a navigation and bombing practice sortie usually involving taking a photo of a light positioned on a prominent feature such as Blackpool Tower or a power station.

CANS - civil air navigation school     CCCS - coastal command communications squadron
CPF - coastal patrol flight     C & L - Circuits and landings

DCO - Duty carried out     DNCO - Duty not carried out

EFTS - elementary flying training school

FAA - fleet air arm     FAF - french air force     FG - fighter group     FIS - flying instructors school
FPP - ferry pilots pool     FS - fighter squadron     FTG - fighter training group     FTU - ferry training unit
FU - ferry unit

HCU - heavy conversion unit     HQSFP - headquarters service ferry pool

IAC - irish air corps

KG - kampfgruppe

MCCF - maintainence command communications flight     MSFU - merchant ship fighter unit
MU - maintainence unit

N/K - not known

OAFU - observers advanced flying unit     OAPU - overseas aircraft preperation unit
OCU - operational conversion unit     OTU - operational training unit

PAFU - pilots advanced flying unit     PR - photo reconnaissance

RBAF - royal belgian air force     RCAF - royal canadian air force     RCN - royal canadian navy
RFS - reserve flying school     RRE - royal radar establishment    RS - radio school     RU (A) - repair unit (aircraft)

SAC - school of army cooperation     SAN - school of air navigation     SFTS - service flying training school
SPTU - staff pilots training unit     SBA - Standard Beam Approach     S&T - supply and transport

TCG - troop carrier group     TCU - transport conversion unit     TEU - tactical exercise unit
TFPP - training ferry pilots pool     TFW - tactical fighter wing     TTU - torpedo training unit

USAAF - united states army air force     USN - united states navy