Special Drawing Rights

pecial Drawing Rights (SDRs) are international foreign exchange reserve assets.[1] Allocated to nations by the International Monetary Fund (IMF), a SDR represents a claim to foreign currencies for which it may be exchanged in times of need.[1]
Today, the US Dollar is the world's primary foreign exchange reserve asset,[2][3][4] and SDRs may be little used.[5] Some nations, notably China and Russia (as well as the UN[2]), favour increasing the substance and function of the SDR.[6][7]
Although denominated in US dollars, the nominal value of an SDR is derived from a basket of currencies, specifically, a fixed amount of Japanese Yen, US Dollars, British Pounds and Euros.[1]

SDRs are the International Monetary Fund's unit of account[1] and are denoted with the ISO 4217 currency code XDR.