When macola adds fields to the files they use this filler & create new ddfs (such as the 103 release, then 103d). If you use the filler, you should start at the end of the file & work forward. You may also need to modify your ddfs if you need reporting, indexing, etc. It's pretty risky if you haven't gone through all the developer training, etc. Several of the long-time cobol developers have used this technique successfully, so you might want to contact one of them for more info. Peak Data, IPS, Saturn Business, SCSI, etc.