When a School Taken (HIS.ST) is on a transcript that does not have a corresponding record in the Course History Institutions (CHI), the School Taken for that grouping will be blank.

Here is a query that will find these records:

LIST STU HIS CHI STU.SC STU.ID STU.GR HIS.YR HIS.GR HIS.CN HIS.ST CHI.NM CHI.TY CHI.ID IF CHI.ID = NULL AND HIS.ST # NULL