Historically on either an 029 or an 129 keypunch machine, when a field was duplicated from the previous record, it was possible to repetitively duplicate that field regardless of formats changing.

Came From Micro Data Conversion

To assist in easily converting a large number of Micro Data Key Entry programs, verify correction support of this feature has been added to Unibase by DMAC release 7.44i with an environment variable "UBDD."

UBDD Set In Environment

Without the UBDD environment variable set, when a rcd-to-rcd duplicated field is corrected in verify mode, the correction is propagated only until the format changes. Now with the UBDD environment variable set, in verify mode, when a duplicated field is corrected, the correction is propagated until the same field is no longer marked as rcd-to-rcd dup in the check box edits regardless of format number.

This is just another way the Unibase by DMAC environment supports users by providing the features wanted and needed.