Exonumia
The noun exonumia is from two classical Greek roots: exo, or out-of, and numis, numismatically (coin) related, thus out-of-coins. It covers coin-like objects such as token and medals, and other items used in place of legal currency or for commemoration, including elongated coins, encased coins, souvenir medallions, tags, badges, counterstamped coins, wooden nickels, credit cards, as well as other similar items. It is related to numismatics, and many coin collectors are also exonumismatists.
Exonumia is the term usually applied to these objects in the U.S.A. The equivalent British term is paranumismatica.
Tokens such as bus tokens (transportation tokens), bar or pub tokens, and casino tokens or chips are some of the more common items of exonumia.
Related, but normally considered to be a different branch of numismatics, is odd and curious money.
See also
