SDR means “Special Drawing Right” as defined by the International Monetary Fund. The full description of the SDR can be found at the IMF website. Briefly, the SDR serves as the unit of account of the IMF and some other international organizations. Its value is based on a basket of key international currencies. The SDR is already in use in international regulations covering mandatory aircraft insurance for public transport aircraft.
To view the current conversion rates from SDR’s to other currencies and vice versa see the the IMF website SDR conversion rates.
The G-INFO UK Register website contains an estimate of the minimum insurance requirements for individual aircraft in Pounds Sterling.