A “hallmark”is an official punch, which after an appropriate assay, is impressed or laser engraved on gold, silver, platinum or palladium items, confirming the fineness, karat or purity of the precious metal. Swiss Customs publishes extensive explanatory materials in English, French, German and Italian. This page links to pertinent English pages of the Swiss Customs' website. A broad scope of supplemental materials are supplied by the links.