Per FDA Technical Conformance Guide, *DY variables must be included if a corresponding *DTC variable is included.
However, Sponsors shouldn't receive a warning (and have it impact their score) if they include the null *DY variable when a corresponding *DTC is included (*DTC may be null or partial for all records, especially historical data).
SD1078 occurs when all permissible variables are null, but no message is generated for --DY.
Is it because --DY can be null for all records when there is no RFSTDTC value?