... By default all events flagged for rejection during the chain are physically removed from the output file (to save space) except those OUT_OF_FOV (useful for cosmic-ray background subtraction) and REJECTED_BY_GATTI (used for proton flare rejection). To keep all events in output set rejectbadevents =N. To use a different mask on FLAG set rejectionflag to another hexadecimal value (binary flags are described in evatt , and in the header of the EVENTS table of the event lists). ...