ATIS

Automatic Terminal Information Service - a continuous recording of important information that's broadcast to pilots in busier terminal areas (like an airport) in order to reduce airway congestion.

An ATIS broadcast includes important information such as weather information, runway information, available approaches for the airline, etc. This recording is usually updated every hour or if there's a sudden change in the weather at the airport.

An ATIS broadcast is issued with an identifying code or letter of the ICAO Phonetic Alphabet. As the pilot approaches the airport, they take note of the letter then report this code upon check-in.