Clearance plan
A clearance plan was an order to vacate an area on a starship.
In 2268, Captain James T. Kirk declared clearance plans were in effect aboard the USS Enterprise, and that the corridors were to be emptied of crewmen. This was done to facilitate the escort of the Medusan Ambassador Kollos to his quarters, as his appearance would drive them insane otherwise. (TOS: "Is There in Truth No Beauty?")