This is a comparison of the IOC, FIFA, and ISO 3166-1 three-letter codes, combined into one table for easy reference. Highlighted rows indicate those entries in which the three-letter codes differ from column to column. The last column indicates the number of codes present followed by letters to indicate which codes are present (O for Olympic, F for FIFA, and I for ISO) and dashes when a code is absent; capital letters indicate codes which match; lower case letters indicate codes which differ.
This list only includes nations or territories that have been assigned at least one of these three types of country codes. For a more complete list of countries, see list of countries.
The only ambiguous trigraph is "BRN", which stands for Bahrain in IOC code and for Brunei in ISO code.
Former countries and former country names
Codes are shown with their last year of use.