There are also 4 letter codes for airports, starting with K for airports located in the US. Little Rock Arkansas has a very interesting code since they use the first three letters of the city name preceded by the K. Very appropriate for Bill Clinton’s home state wouldn’t you say?
It's the same code with the country as a prefix. Travele agents drop the country code but ATC and the regulators use them, so Atlanta is ATL or KATL and Toronto is YYZ or CYYZ. The US country code is K.
Try Rapid City, South Dakota. RAP is OK by itself...then you go to the ICAO code, add K on the front, and you get: KRAP.
}:-)4