ENR 1.3 INSTRUMENT FLIGHT RULES
1.3.1. In Instrument Meteorological Conditions, the pilot shall operate in accordance with the instrument flight rules except that within a control zone, a special VFR flight may be authorised.
1.3.2. Flights shall be conducted in accordance with the Instrument Flight Rules (even when not operating in Instrument Meteorological Conditions) when operated:
in class A airspace,
above FL150 in controlled airspace,
above FL250 in uncontrolled airspace, except as approved by the Chief Executive Officer of Civil Aviation Authority of Malaysia.
between the hours of sunset and sunrise, or
within controlled airspace, more than 100NM seaward from the shoreline.
1.3.3. When operating in VMC, on an IFR flight plan, the pilot-in-command shall keep a lookout for other aircraft to avoid collision hazard.
1.3.4. Minimum levels
1.3.4.1 Except when necessary for take-off or landing, or except when specifically authorized by the appropriate authority, an IFR flight shall be flown at a level which is not below the minimum flight altitude established by the State whose territory is overflown, or, where no such minimum flight altitude has been established:
over high terrain or in mountainous areas, at a level which is at least 600 m (2 000 FT) above the highest obstacle located within 8 km of the estimated position of the aircraft;