Many Swiss banks offer precious metal safekeeping services or deposits. When you bring precious metals like Gold, Silver, Platinum or Palladium to the bank for safekeeping, the bank issues gold certificates which serve as claims for the delivery of the corresponding amount of precious metal.
Allocated certificates serve as title deeds, meaning they name you as the owner of specific precious metal bullion. Unallocated certificates, on the other hand, do not serve as title deeds to specific pieces of bullion. Instead, they serve as a claim to a specific amount of precious metal which the holder can withdraw upon request.
Holding allocated certificates may incur storage fees and taxes because you are actually legal owner of physical gold. These fees and taxes do not generally apply to holding unallocated certificates because they do not represent ownership of precious metals but only a claim for delivery of precious metals upon request.