Editing spots and links in the TrackScheme views.

Action	Key
Editing spots.
Remove a spot.	Press D with the mouse inside the spot to remove.
Edit the label of a spot.	Press Enter when a spot is focused, then enter its label and press Enter to validate.
Creating links between spots.
Create a link between two spots.	Press and hold L with the mouse inside the source spot. Release L when inside the target spot.
Remove a link.	Press D with the mouse on the link to remove.
Selection editing.
Add a spot / link to the selection.	Shift-click on a spot or a link to add / remove it to / from the selection.
Select all in a box.	Click and drag a box. Shift-click and drag to add the content of the box to the current selection.
Clearing the selection.	Click on an empty place of the image.
Remove selection content.	Shift-delete.
Undo / redo.
Undo.	Control-Z.
Redo.	Control-shift-Z.