Location = Clear of A, B, C and D
Active aerodromes
Built-up areas
Controlled airspace
Danger areas.
Incidentally, 'A' is indeed for 'airframe'. It's not just 'airframe = flaps up', there will be occasions when other configurations are deliberately used - such as flaps extended, landing gear down etc etc. Also, if you're going to be spinning, it is an opportune point at which to recall the max. fuel imbalance permitted, although that could also be covered under 'E' for engine.
The transfer of military methods into civilian practice is often eroded over the course of time - such as the misuse of 'P_A_T' as 'A_P_T' instead of 'S_H_T', for example. But I was taught the same HASELL checks in Cessna 150s back in 1968 as I was in RAF Chipmunks, Jet Provosts, Gnats, Hunter, Bulldogs etc etc over the years, so it is emphatically NOT
an "Air Force ism" appropriate to the high performance aircraft that they fly, but just mindlessly carried over to light aircraft operations and passed down from instructor to instructor with no critical thought as to whether it actually had any value.
Actually, I'm surprised you don't advocate conducting one of your half hour monologues before stalling, BPF.....