Zoom H4n Pro Operation Manual page 99

During recording and playback, you cannot make any settings
after Step 3 of AB REPEAT.
When moving around using FF and REW
buttons, if you press the button for less than
2 seconds (quick press), it will move to the
next mark.
Press and
Press the FF and REW buttons for more than
2 seconds to search for a desired point.
After setting up A and B points, press the REC button to
cancel all settings.
Set/clear A and B points
Stop
Hold for more than one second to search
backward or forward
this will move to the nearest mark instead)
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