Update control filesEdit online The process option UPDCNTL produces a control file that relates matches, insertions, deletions, and reformats to: The relative line numbers of the old and new files (LINE compare type); see Figure 1. The relative word position of the old file (WORD compare type); see Figure 1. The relative byte offset (BYTE compare type); see Figure 1. Note: No source or data from either input file is included in the update file produced by UPDCNTL.