The French coin of old is composed of two parts: the ECU (3 letters) and the SOU (3 letters). The ECU, which stands for 'European Currency Unit', was a unit of account used by the European Community from 1979 to 1998. It was replaced by the Euro in 1999. The SOU, which stands for 'Solidus', was a gold coin used in France from the Middle Ages until the French Revolution. It was replaced by the Franc in 1795.