The Good Delivery specification is a set of rules issued by the London Bullion Market Association (LBMA) describing the physical characteristics of gold and silver bars used in settlement in the wholesale London bullion market. It also puts forth requirements for listing on the LBMA Good Delivery List of approved refineries.
Good Delivery bars are notable for their large size and high purity. They are the type normally used in the major international markets (Hong Kong, London, New York, Sydney, Tokyo, and Zürich) and in the gold reserves of governments, central banks, and the IMF.