You can erase the track mark that is located at just before the current position.
PLAY/STOP・ENTER.

“Erase Track Mark?” is displayed and the track mark indicator and the track mark number to be erased will flash.
or
+ to select “YES,” and then press
PLAY/STOP・ENTER.
The “Erasing...” animation appears in the display window and the selected track mark will be erased.

A. Before erasing a track mark:
is the stop position.
B. After erasing a track mark: The track mark just before the stop position will be erased.
(stop) to exit the menu mode.
PLAY/STOP・ENTER.