All watch-cases in gold, silver, platinum or palladium, of foreign or local manufacture, sold in Switzerland, are subject to control and compulsory official marking.
Apart from watch-cases, that is for all other precious metal articles, and multimetal goods, the control procedure is optional.
A single official hallmark will be used for all precious metals and all fineness standards, the "head of a St. Bernhard dog":

The official hallmark bears the distinctive symbol of the Assay Office, which is positioned at the spot marked with an X.
Distinctive symbol: | Biel/Bienne | B |
Chiasso | T |
|
Genève | G |
|
La Chaux-de-Fonds | C |
|
Le Noirmont | J |
|
Zürich | Z |
International conventions