Post AOC in prominent place
Remmeber when in the gfood old days, the CAA issued a little sticker saying AOC holder.
The MCA (yachties version), issue an annual sticker.
The DVLA, have had plenty of prac tice too.
Just how complex would it be for all national authorities to issue a similar sticker, to be located inside the aircraft, to the left of the main entrance door.
It would solve many "problems".
windy pops