Instrument Flight Rules

Instrument Flight Rules (IFR) are a set of regulations and procedures for flying aircraft whereby navigation and obstacle clearance is maintained with reference to aircraft instruments only and separation from other aircraft is provided by Air Traffic Control. It is an alternative to visual flight rules (VFR), where the pilot is ultimately responsible for navigation, obstacle clearance and traffic separation using the see-and-avoid concept. The primary benefit of these regulations allow an aircraft to safely fly through clouds, which is not permitted under VFR.
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Rules governing the procedures for conducting instrument flight. Also a term used by pilots and controllers to indicate type of flight plan. (FAA2) (FAA4) (FAA6) (FAA13) (FAA14)

[ICAO]
A set of rules governing the conduct of flight under instrument meteorological conditions.
 

Rules governing the procedures for conducting instrument flight. Also a term used by pilots and controllers to indicate type of flight plan.
(See INSTRUMENT METEOROLOGICAL CONDITIONS.)
(See VISUAL FLIGHT RULES.)
(See VISUAL METEOROLOGICAL CONDITIONS.)
(See ICAO term INSTRUMENT FLIGHT RULES.)
(Refer to AIM.)