Definition
Information printed in the borders of an aeronautical chart that identifies the chart and explains how to use it. Margin identification typically includes the chart name, edition number, effective dates, scale, projection, legend references, and procedural notes printed outside the main chart image.
Plain English
The printed information around the edges of a chart that tells you which chart it is, when it's valid, and how to read it correctly.
Context Anchor
Seen when reading or checking aeronautical charts, especially before using a chart for flight planning or navigation.
Derivation
Margin comes from the Latin margo, meaning 'edge' or 'border.' Identification here keeps its plain meaning: information that identifies. Together: the identifying information placed around the edge of the chart.
Why Pilots Care
Ensures the pilot confirms they are using the correct and current chart before relying on it for navigation or approach guidance.
Intuition Check
Do not read margin as a safety cushion here. In this context, margin means the printed edge or border of the chart.
Example Sentence 1
During preflight, she checked the margin identification on the approach plate to confirm the chart was within its current cycle.
Example Sentence 2
During the flight briefing the instructor pointed out the margin identification so the student could verify the chart matched the planned route.