New fields, added in the MSS DataServer, will now get a higher field number than the existing fields. This avoids position conflicts with any existing fields in the table. Existing fields will retain the rpos throughout their life time and will never change once assigned an rpos. If a field is deleted, rpos of that field will not be reused an it leaves a hole in the rpos structure. However the DataServer for MS SQL server, rpos of a deleted field may be reused by new field, if the new field is added from a .df file that has the same position attribute as that of the deleted field rpos.