A stamp act is any legislation that requires a tax to be paid on the transfer of certain documents. Those who pay the tax receive an official stamp on their documents, making them legal documents. A variety of products have been covered by stamp acts including playing cards, dice, patent medicines, cheques, mortgages, contracts, marriage licenses and newspapers. The items may have to be physically stamped at approved government offices following payment of the duty, although methods involving annual payment of a fixed sum or purchase of adhesive stamps are more practical and common.