Engine Ratings

ICAO-established information included in the engine type certificate data sheet of ratings and limitations based on the specified operating conditions and any other information found necessary for safe operation of the engine.
Engines are certified to deliver standard thrusts depending upon flight conditions. Thrust is typically measured in kN or lbs. A 'rating' is a predefined power setting that the pilot can select which may be appropriate for particular flight conditions. Rating terminology differs between civil and military aircraft, reflecting the different requirements of these types of aviation.
The following ratings are typical of commercial airliners. The aircraft/engine manufacturer will have to declare two principal ratings to the certifying authorities, since these define the safe limits of operation of the engine/aircraft - these are the Maximum Take-Off (MTO) rating, and the Maximum Continuous Thrust (MCT or MCN) rating.
-Maximum Takeoff thrust (MTO)
-Maximum Continuous thrust (MCT)
-Maximum Climb thrust (MCL)
-Maximum Cruise thrust (MCR)
-Flight Idle
-High or Approach idle
-Ground Idle
Military Thrust
Typically used to define the maximum available thrust without use of reheat. Sometime referred to as max 'dry' thrust.