The reserved alpha-3 codes can be divided into the following four categories : exceptional reservations , transitional reservations , indeterminate reservations , and codes currently agreed not to use .
The following alpha-3 codes are subject to an exceptional reservation : The following three codes were also under exceptional reservation , until the update from 2006-03-29 included them in the standard : The following alpha-3 codes are subject to a transitional reservation : The following alpha-3 codes are subject to an indeterminate reservation , having been notified to the United Nations Secretary-General under the 1949 and\/or 1968 Road Traffic Conventions : The following code has been reassigned : For the time being , ISO 3166\/MA has agreed not to use the following codes , taken from ISO\/IEC 7501-1 ( machine readable travel documents ) , as alpha-3 country codes :