"Remove before flight" ribbons (photo), are used as safety warnings for quick and easy visual location, seen on removable aircraft components, typically in the form of a red ribbon, and clearly marked with the words "Remove before flight". They indicate that devices, such as a protective covers, or pins to prevent the movement of mechanical parts, or control locks, and are to be used only when the aircraft is on the ground.
They must also be installed by mechanics on the main landing and nose gear for towing the aircraft or during maintenance operations. In the case of prolonged periods of the aircraft on the ground, or when necessary, we can also see these ribbons connected to the protective covers on static pressure ports or pitot probes toward the aircraft’s nose for protection.
The "remove before flight" ribbons are normally stored in the cockpit, as part of the pilot’s check list procedure upon taking charge of the plane.