DEFINITION: ISO is the International Standards Organisation ISO has specified 3 letter codes for most, if not all currencies in the world. Although the standard can be purchased from ISO's web site, the codes are often published by data vendors and in market literature.
DEFINITION: Official exchange rate refers to the exchange rate determined by national authorities or to the rate determined in the legally sanctioned exchange market. It is calculated as an annual average based on monthly averages (local currency units relative to the U.S. dollar).