Caravan tyre speed rating rules in France ????

Quasar524

I believe I read somewhere a good few years ago that in France caravan tyres are required by law to have a speed rating equal to the maximum legal speed for the type of road on which you are driving.  I had a scan through the overseas travel section on this
site but could find no info. Does anyone know if such a rule does exist, is an urban myth, or a figment of my imagination.  And if it does exist, where can I get reliable information?