The ouguiya is the official currency of Mauritania and currency code is MRO. It is divided into 100 centimes and is abbreviated as UM. The ouguiya was introduced in 1973, replacing the CFA franc at a rate of 1 ouguiya = 5 francs. In 1973, coins were introduced in denominations of 1, 2½, 5, 10 and 20 centimes and ½, 1 and 2 ouguiyas.The name "ouguiya" comes from Berber language وغية (wəġiːyah) meaning "ounce". A common nickname for the coin was khoums (Arabic: خمس khums), which means "fifth", referring to its former value relative to the French franc; this term is still used colloquially for both money and fractions thereof throughout much of Francophone Africa.