Rare US Dollar Bill

Cubans call the U.S. dollar "fula". Loosely translated from cuban jargon mean bad or not good. American money was not bad to have or use by cubans in the island, but it's posession was penalized before the mid-90's, hence the nickname.
Dollar sign
The symbol $, usually written before the numerical amount, is used for the U.S. dollar (as well as for many other currencies). The sign's ultimate origins are not certain, though it is possible that it comes from the Pillars of Hercules on the Spanish Coat of arms on the Spanish dollars that were minted in the New World mints in Mexico City, Potosí, Bolivia, and in Lima, Peru. These Pillars of Hercules on the silver Spanish dollar coins take the form of two vertical bars (||) and a swinging cloth band in the shape of an "S".