Monetary operations refer to the implementation of monetary policy – ensuring that a central bank’s policy decision has the intended impact on financial markets, and on the economy more generally. For operational purposes the day-to-day tactical target is usually to achieve a particular level of interest rates or the exchange rate; and the most efficient instruments are those which best complement the workings of a market system. This Handbook examines the various different instruments: open market operations; standing facilities; and both required reserves (which have some of the characteristics of direct controls), and voluntary or contractual reserves. Open market operations are undertaken at the initiative of the central bank, whereas standing facilities are used at the initiative of the commercial banks. Participation in both is voluntary at the level of individual banks, whereas in most countries reserve requirements are an administrative imposition on all banks - albeit one which, through averaging, allows them a degree of day-to-day flexibility. Monetary instruments are not only used to implement monetary policy; they are also used for liquidity management. This is an essential part of the central bank’s operations, in order to prevent the short-term uncertainty and price volatility which day-to-day swings in market liquidity would otherwise cause. The Handbook therefore also considers liquidity forecasting and management issues.