RedED
The FR machines had 26k thrust allowable to them this could be de-rated by using a fixed de-rate to 24k or 22k with further reduction through using assumed temperature. These processes however are down to the operating crew taking into consideration the performance. It was not the case thye had 26k engines permanently de-rated to 24k from the factory.The 800 suffered at BHD with it either carrying full load but not enough fuel for European destinations or carrying the fuel but suffering a penalty with regards to passengers.
Regards