I think I read that this piece of inspired legislation is for visibility to traffic should a motorcyclist come off at night and be lying in the road.
needs to be reflective, hi-vis not enough...
I went to Le Mans for the Moto GP last year & Plod pulled every motorcyclist leaving the motorway to one side to check paperwork etc.
I don't recall any helmets with reflective stickers on (mind I wasn't looking for them) & I certainly haven't stickered mine up & none of us were fined to the best of my knowledge, certainly I wasn't.
That said I do wear a full High Viz jacket, with reflective strips sewn in. Maybe that cut me some slack?
On the other hand maybe the French police are facing cuts in these times of austerity & have decided to start invoking this old rule as a way of increasing revenue?
I guess the next few weeks will tell us more as we all come out of hibernation & start heading Sous La Manche.
It would be good to hear any anecdotal evidence before I head that way in late May.