The $UNQREC function is used in conjunction with the ON FIELD CONSTRAINT CONFLICT unit and the UNIQUE field attribute.
If $UNQREC is invoked from an ON FCC unit following the detection of a uniqueness violation, it returns the record number of the record already containing the field name = value pair. At all other times, $UNQREC returns -1.
Use $UNQREC in conjunction with $UPDREC to find the record number of the unique record already stored ($UNQREC) and the record number of the non-unique record you are attempting to store ($UPDREC). The $UNQREC function takes no arguments.