The airport code for Hamilton Airport - Australia - is HLT.
The airport code for Albany Airport - Australia - is ALH.
The airport code for Bathurst Airport - Australia - is BHS.
The airport in Perth is very origionally named and is called "Perth Airport"
The airport code for Jammu Airport is IXJ.
The airport code for Shannon Airport is SNN.
The airport code for Miyako Airport is MMY.
The airport code for Zagreb Airport is ZAG.
According to a search of the internet, there is a small airport with the code IDK in Indulkana, Australia.
Honolulu, HI - Honolulu Airport (HNL).
The airport code for Gao International Airport is GAQ.
The airport code for Munich Airport is MUC.