Plain English Meaning
A blue box on an approach chart that draws your eye to information that applies only to this airport, not to airports generally.
Full Definition
On an FAA instrument approach chart, a light blue (cyan) rectangular box drawn around a piece of information to highlight that it is specific to a particular airport — most commonly used to enclose airport-specific notes, alternate minimums references, or take-off minimums references that apply only to that airport.
Context Anchor
Seen on electronic charts or moving-map displays when selecting an airport to view more details.
Derivation
‘Cyan’ comes from the Greek ‘kyanos,’ meaning dark blue. On FAA charts, cyan (light blue) is used as a deliberate visual code — different from the black text and brown terrain shading — so the eye picks airport-specific information at a glance.