A Starfleet general order covering the approach of a vessel with which communication has not been established, which Saavik tries to quote as the hijacked Reliant closes on the Enterprise.
General Order 12 sets out the precautions a starship must take when another vessel approaches without answering hails. Its full wording is never heard on screen, because the one officer who starts to recite it is cut off.
The order features in Star Trek II: The Wrath of Khan. As the USS Reliant draws near in silence, Lieutenant Saavik begins to quote General Order 12 to Admiral Kirk, and Spock stops her by pointing out that the admiral knows the regulations. Kirk goes only as far as yellow alert and leaves the shields down, and Khan, who has seized the Reliant, opens fire and cripples the Enterprise.
Kirk afterwards admits his mistake and tells Saavik to keep on quoting regulations. The moment is one of the film's clearest signs that he has grown rusty behind a desk.