Undo / redo element changes

Undo adding, deleting or structurally moving an element, plus class, attribute and tag changes made through DBE, from the confirmation message or with Cmd/Ctrl+Z. A deleted element is restored, an added element is removed, and a reordered, indented or outdented element returns to its previous position. The message then offers Redo; Cmd/Ctrl+Shift+Z also redoes the change. Other settings changes are not covered.