Question: How do I use index marks?
To insert an index mark, press the INDEX button during recording or playback to set an index mark. An index number appears on the display.
To locate an index mark during playback, hold the FF or REW button while playing a file. The recorder stops for one second when it reaches an index mark.
To clear an index mark, locate the index mark you want to clear. Press the ERASE button while the index number appears for approximately two seconds on the display. The index mark will be erased.
Verification Source: Olympus Website