Derived Records and the use of --DRVFL
Although it is implicit in the general concept of a derived record that there is no collected result (--ORRES should be null), this is not an explicit requirement currently stated in published CDISC material. This is being evaluated for clarification in a future release of the SDTMIG and/or Model document.
Use of --LNKID and --LNKGRP
The definition of --LNKID says that it is "used to identify a record," and the definition of --LNKGRP says that it is "used to identify a group of records." This implies that when setting up a relationship in RELREC, a row where RELTYPE = ONE will have an IDVAR of --LNKID (and not --LNKGRP); a row where RELTYPE = MANY will have an IDVAR of --LNKID (and not --LNKGRP). The examples in this version of the SDTMIG have not been systematically reviewed to implement this distinction between --LNKID and --LNKGRP. This distinction between --LNKID and --LNKGRP, and the appropriateness of using other identification variables for linking, will be clarified in a future release of the SDTMIG and/or Model document, and at that time examples in the SDTMIG will be systematically reviewed and updated to reflect that clarification.