The national no-fly list is maintained by the Directorate General of Civil Aviation to check unruly and disruptive behaviour on an aircraft. Any behaviour, from verbal harassment to life-threatening acts, is supposed to be reported by the pilot in command of the aircraft, following which an internal committee of the airline concerned takes a call within 30 days on the gravity of the reported act and an appropriate duration of the ban. Level 1 offences attract up to three months on the no-fly list, Level 2 up to six months and Level 3 for at least two years or more. Other airlines may choose to follow suit.