Great question - EXT to PER just means Exeter Airport to Perth Airport. Now you’ll know what these unique codes when you look for flights! While you’re still figuring out your travel plans, it’s not a bad idea to learn the names and codes of other airports around these areas: Broome Airport (BME), Geraldton Airport (GET), Karratha Airport (KTA), Learmonth Airport (LEA), Kalgoorlie Airport (KGI).