Which feature is used to uniquely identify an ATIS broadcast?

• A. Time stamp
• B. Call sign sequence
• C. Phonetic letter code
• D. Date stamp

Answer: (C)

The main idea is that ATIS uses a running information letter to identify the current broadcast version. This phonetic letter code (for example, Information Charlie) is spoken as part of the ATIS message and changes whenever the weather, runway, or other important details update. Because the letter changes with each update, it uniquely tags the exact ATIS cycle you’re receiving, so pilots and controllers are sure they’re talking about the same information.

Time stamps or date stamps aren’t the primary cue pilots use in-cockpit to verify the ATIS version, and a call sign sequence isn’t how ATIS identification works. The phonetic letter code is the standardized way to uniquely identify the current ATIS broadcast.