It must be invoked with either a logical keyword on the command line to specify the mode of operation, or using the PROMPT keyword. The modes available are:
CQUALITY IGNORE - Sets the temporary bad quality bit, (=CIGNORE) leaving the rest unaltered. CQUALITY RESTORE - Clears the temporary bad quality bit, (=CRESTORE) restoring the original quality value. CQUALITY SET - Sets quality to a specified value. (=CSETQUAL) CQUALITY NOT - Complements existing quality values. CQUALITY AND - ANDs existing quality with specified value. CQUALITY OR - ORs existing quality with specified value. CQUALITY EOR - EORs existing quality with specified value.