Currency money or book money, which are fiat 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
Shall and will The IETF (Internet Engineering Task Force) defines "shall" and "must" as synonymous terms denoting absolute requirements, and "should" as denoting a somewhat flexible requirement, in RFC documents. On specifications and standards published by the United States Department of Defense (DoD), requirements with "shall" are the mandatory requirements. (“Must” shall not be used to express mandatory provisions. Use the term “shall.”) “Will” declares intent or simple futurity, and “should” and “may” express nonmandatory provisions. Outside DoD, other parts of the U.S. government advise against using the word "shall" for three reasons: it lacks a single clear meaning, it causes litigation, and