ICAO shares Standards and Recommended Practices(SARPs) for airport signs, runway and taxiway markings, mandatory instruction signs, information signs, mandatory instruction markings, runway holding position markings, etc. via Annex 14, Aerodromes. MANDATORY INSTRUCTION SIGNS A mandatory instruction sign indicates a location beyond which an airplane may not proceed unless authorized by air traffic control. At uncontrolled … Continue reading ICAO recommended Airport Signs, Runway and Taxiway Markings