Creo™ Schematics 4.0 Help Center > Working with Designs > Trail Files > About Trail Files
  
About Trail Files
Trail files are editable text (.bac) files that record all menu and dialog box commands, selections, and keyboard entries for a particular working session. When you run a trail file, the system replays your actions in the original order. You can use trail files to view a previous working session (or to recover from an abrupt session termination, although the Auto-save system is most reliable for this sort of recovery).
To control the display during trail file playback click File > Options > Environment.