Source countries of covered commodities should be identified using “abbreviations and variant spellings that unmistakably indicate the country of origin.” U.S. represents the United States and the abbreviation “U.K.” can represent “The United Kingdom of Great Britain and Northern Ireland” according to AMS. The useful list of acceptable abbreviations, however, is very limited and examples such as “CAN” for Canada and “MEX” for Mexico have been rejected by AMS.  In addition, symbols or flags alone are not acceptable.