Ordonnance sur les zones agricoles, 7 December 1998
 

In Switzerland, the surface used for agricultural purposes is divided in regions and zones in the register of agricultural production ("cadastre").  Article 1 of this prescription provides that the mountainous region is divided in four zones (I to IV). Article 2 gives criteria to define these zones (weather conditions, lines of communication, etc.). Article 6§1 provides that the Federal Office for Agriculture (FOAG) can change the boundaries of these zones under certain conditions.