Undoing and Redoing Commands
Almost every DDD command can be undone, using Edit => Undo or the Undo button on the command tool.
Likewise, Edit => Redo repeats the command most recently undone.
The Edit menu shows which commands are to be undone and redone next; this is also indicated by the popup help on the Undo and Redo buttons.
Node:Customizing, Previous:Undo and Redo, Up:Windows