How are letter-letter-number identifiers categorized?

Letter-letter-number identifiers are used to categorize smaller, secondary aerodromes. These identifiers provide a systematic way to designate smaller airports that may not be as widely recognized as primary airports but still serve an important role in the aviation system. This categorization helps pilots and air traffic controllers identify these locations easily, ensuring safe and efficient operations, especially in areas where larger airports are not present.

Primary airports typically use three-letter identifiers, while military bases and private airstrips have their own identification systems that generally do not follow the letter-letter-number format. Each type of aerodrome has specific identifier conventions to streamline aviation operations and enhance safety.