Unit of account L.S.D units in ratio 240:12:1. The Florentine gold florin, the French franc and the electoral rheingulden all became pounds (240 denari) of account. Units of account would often survive over 100 years despite the original coins changing composition and availability (e.g. the Castilian maravedi). A modern unit of account is the European Currency Unit, used in the European Union from 1979 to 1998; its replacement in 1999, the Euro, was also just a unit of account until the introduction of notes and coins in 2002. Unit of account is the main way of calculating a carrier or ship owner's liability
Currency pair a dot or a dash. A widely traded currency pair is the relation of the euro against the US dollar, designated as EUR/USD. The quotation "EUR/USD 1.2500" means that one euro is exchanged for 1.2500 US dollars. Here, EUR is the base currency and USD is the quote currency(counter currency). This means that 1 Euro can be exchangeable to 1.25 US Dollars. The most traded currency pairs in the world are called the "Majors". They involve the currencies euro, US dollar, Japanese yen, pound sterling, Australian dollar, Canadian dollar, and the Swiss franc. Currency quotations use the abbreviations for currencies