blind pew : but who in the military in France obeys that!
Well in France ( and some other EU countries) it is quite well regulated. The low level corridors are on the maps with numbers and the respective activation times are on the military Notams that anyone wanted to fly in them should consult before ( or ask the FIS) .
. ULM ( ultra lights) "airfields" are just like private landing strips. They are registered but are not protected against low levels military in the corridors. Golden rule we all do : Check the Notams before using the airspace.