This is defined as Hamilton Island Airport (HTI) and Brussels Bruxelles-National Airport (BRU). Codes like Brussels Bruxelles-National Airport are often used to just call airports uniquely. 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: Charleroi Brussels Airport (CRL), Antwerp Deurne Airport (ANR), Ostende-Bruges Airport (OST), Liège Bierset Airport (LGG).