Why is the designation for Switzerland "CH"?

Question

Swiss autos bear the symbol "CH" in the oval sticker on the rear of the car.

Answer 1

CH stands for Confoederatio Helvetica

and it doesn't stand only on the stickers on the rear of cars but also on Swiss related web addresses (see below)

once again, the information site of Switzerland

http://www.about.ch/

Answer 2

Go back and read De Bello Gaullico,  Switzerland is the land of the Helvitii --- CH is the community of the Helvetii

Answer 3

The letters CH represent the abbreviation for the name of Switzerland in Latin.  This was done in order to avoid favoring one of Switzerland's official languages over the other.  The official languages are: German, French, Italian and Romansch.  For the same reason, Swiss stamps say "Helvetica" not Suisse, Schweiz, etc.