When I use P21 to validate sdtm data, this message “DSDECOD value not found in ‘Completion/Reason for Non-Completion’ extensible codelist when DSCAT == ‘DISPOSITION EVENT’” occurred, because there are some DSDECOD are not controlled terminology values. but when I validated again, this message didn’t occur, I’m confused, for the same data, why this message occurred some times. Anyone know it? thanks!