Plain English Meaning
The set of signs around an airport that tell pilots where they are, where they can go, and where they must stop. The colors and shapes of the signs each have a fixed meaning.
Full Definition
The system of standardized signs installed at an airport to give pilots location, direction, runway, and instructional information while taxiing. Airport signs use specific colors and shapes to convey meaning: red signs with white lettering indicate mandatory instructions (such as runway holding positions), yellow signs with black lettering provide direction or location information about taxiways, and black signs with yellow lettering identify the taxiway the aircraft is currently on.
Context Anchor
You encounter signage while taxiing before takeoff, after landing, or any time you are moving the on the airport .