Postage stamps and postal history of Costa Rica change in currency from "Reales" to the new Pesos and "Centavos", the issue of 1863 was surcharged with new values for postal use: 1 Centavos, 2 Centavos, 5 Centavos (all over the Medio Real stamp), 10 Centavos (over Dos Reales) and 20 Centavos (over Cuatro Reales). The 5, 10 and 20 Centavos were also surcharged "U.P.U." Costa Rican stamps were issued overprinted "Guanacaste" in 1885-89 following war with Nicaragua over the sovereignty of Guanacaste. The first issue in the new "Colón" currency was dated 1900 and put into circulation in 1901. It consists of ten stamps with values ranging from
Currency money Currency money Currency money is money in full circulation that takes its value from the precious metal it contains, that is, its market value is (almost) the value of the metal it contains (apart from the Seigniorage or the minters' profit), though this is always overcompensated for in coins and banknotes from a country undergoing debasement. Currency money is usually made of silver or gold, but in very rare cases plated metal and even copper may be used. Currency money is commodity money, as opposed to coins whose metal value is less than their nominal value, paper money, and deposit