The Undo/Redo Actions

The typical undo and redo actions are available in Oxygen XML Editor:
Undo Ctrl Z (Command Z on OS X) - menu Edit > Undo
Reverses a maximum of 200 editing actions (configurable in the Editor preferences page) to return to the preceding state.
Note: Complex operations like Replace All or Indent selection count as single undo events.
Redo Ctrl Y (Command Z on OS X) - menu Edit > Redo
Recreates a maximum of 100 editing actions that were undone by the Undo function.