Paragraph 3 Misuse of signals and markings
A signal or marking which is given a meaning by Section IX or which is required by Section IX to be used in specified circumstances or for a specified purpose shall not be used except with that meaning, in those circumstances or for that purpose.
A person in an aircraft or on an aerodrome or at any place at which an aircraft is taking off or landing shall not—
make any signal which may be confused with a signal specified in Section IX; or
except with lawful authority, make any signal which he knows or ought reasonably to know to be a signal in use for signalling to or from any of Her Majesty’s naval, military or air force aircraft.
Signals prescribed in accordance with general international aeronautical practice for the purposes of search and rescue shall not be used for any purpose other than that intended.