currency controls

Foreign exchange controls are various forms of controls imposed by a government on the purchase/sale of foreign currencies by residents, on the purchase/sale of local currency by nonresidents, or the transfers of any currency across national borders. These controls allow countries to better manage their economies by controlling the inflow and outflow of currency, which may otherwise create exchange rate volatility. Countries with weak and/or developing economies generally use foreign exchange controls to limit speculation against their currencies. They may also introduce capital controls, which limit foreign investment in the country.

View More On Wikipedia.org