These are the marks that are stamped on a precious metal object. Their role is, for example, to identify the maker of the object, guarantee the standard of fineness of the precious metals used and attest that the duties owed to the assay office for control of the objects have been paid. A single item can therefore be stamped with several hallmarks. Two hallmarks are obligatory in France: the standard mark and the sponsor’s mark. The standard mark only appears on objects that have been proven to contain the legally required proportion of gold, silver or platinum. The sponsor’s mark, the second obligatory hallmark for gold, silver and platinum objects, was introduced in France in 1355 by King John the Good. A jeweler must register its mark with the assay office by inscribing it on a plate of copper. The assay office ensures that no two jewelers use the same mark.