The ISO 4217 international standard of the International Organization for Standardization (ISO) is "Representation of Currency and Funds Codes".

A currency code is a code assigned to a currency for trading purposes. It is typically represented by three uppercase English letters, where the first two letters generally represent the country name, and the last letter represents the currency name. For example, the United States Dollar is represented by USD. There are over 150 countries and regions worldwide, and approximately 30 currencies are actively traded. For these 30 currencies, each has 29 exchange rates against other currencies, resulting in a total of 435 different exchange rates.