Switzerland has concluded free trade agreements with a number of countries. The preferential treatment granted under these agreements applies only to goods which comply with the origin provisions, however.
The existing free trade agreements can be found at the following link: R-30 Free trade agreements, preferential tariffs and origin of goods (available in German, French and Italian).
Preferential tariffs are customs facilities (duty-free or reduced tariff rate). They are granted only to goods which comply with the rules set out in the free trade agreement, i.e. they must in particular demonstrate origin as required by these agreements.