SORT/MERGE statement notes

If records are reformatted by INREC (SORT and MERGE) or E15 (SORT), FIELDS must refer to fields in the appropriate reformatted records.
If SZERO is in effect, -0 collates before +0 in ascending order and after +0 in descending order when numeric fields are sorted or merged. If NOSZERO is in effect, -0 collates equally with +0 when numeric fields are sorted or merged. However, SZERO is always used for a conventional merge or tape work data set sort application.