if there is no place in the plane where we can see those civil marks, and even the crew use the ones painted on the tail/fuselage when questioned, whats the purpose of these "F-" civil ones?
FWIW an FAF Airbus was parked up at the Terminal at Blagnac (LFBO) the other day and it was definitely was wearing its "F-" civvie reg on the rear fuselage...(no, I didn't log it..)
Another one here:
F-ZWUG Armée de l'Air (French Air Force) Airbus A330-223 - Planespotters.net Just Aviation