Code Value Notes
Alpha-2 BT Alpha-2 code from ISO 3166-1
Alpha-3 BTN Alpha-3 code from ISO 3166-1
Numeric 064 Numeric code from ISO 3166-1
ITU BTN Codes assigned by the International Telecommunications Union
FIPS BT Codes from the U.S. standard FIPS PUB 10-4
IOC BHU Codes assigned by the International Olympics Committee
FIFA BHU Codes assigned by the Fédération Internationale de Football Association
DS   Distinguishing signs of vehicles in international traffic
WMO   Country abbreviations used in weather reports from the World Meteorological Organization
GAUL 31 Global Administrative Unit Layers from the Food and Agriculture Organization
MARC bt MAchine-Readable Cataloging codes from the Library of Congress
DIAL 975 Country code from ITU-T recommendation E.164 (international dialing code)
TLD .bt Country code Top Level Domain