"A revenue stamp, tax stamp or fiscal stamp is a type of adhesive label used to collect taxes or fees on various items. Many countries of the world have used them, for documents, tobacco products, liquor, drugs, playing cards, hunting licenses and other kinds of things. While revenue stamps often resemble postage stamps, they were not intended for use on mail and therefore did not receive a postal cancellation. However, revenue stamps can display cancellation markings, three types being by manuscript signature of the person canceling the stamp (usually with date), by hand stamp identifying the canceling agent (also usually with date), or by punch; otherwise, they may be simply affixed to a product in such a way so as to be invalidated or destroyed upon its unpackaging." http://en.wikipedia.org/wiki/Revenue_stamp

"revenue stamp = A stamp affixed to an item as proof that a government tax has been paid. "
http://dictionary.reference.com/browse/revenue stamp

"In order to help finance the Civil War, the U.S. government collected a few cents from every official transaction that involved the exchange of money. For instance, the government collected revenue from the sale of deeds, mining claims, mortgages, insurance policies, receipts, playing cards, and, of course, stocks and bonds. Initially, revenue was collected by attaching adhesive revenue stamps to documents. (...) It quickly became apparent that adhesive stamps were cumbersome, so Congress enacted a law effective October 1, 1862 allowing revenue stamps to be pre-printed on certain kinds of documents."
http://www.coxrail.com/RNs.htm

A evo i nekih primjera biljega (u slikama)
http://www.battleship-revenues.com/
http://www.useless.connectfree.co.uk/revenue/revenue.htm