LAO stands for Laoag Airport, while BRU stands for Brussels Bruxelles-National Airport. These codes are often called IATA codes, a set of identifiers established by IATA (International Air Transport Association) that is widely used by airlines and the aviation industry. Charleroi Brussels Airport (CRL), Antwerp Deurne Airport (ANR), Ostende-Bruges Airport (OST), Liège Bierset Airport (LGG) are some additional IATA codes for airports related to your trip.