The Undo command (Edit | Undo on the Menu bar; Ctrl-z on the keyboard) lets you undo (cancel) one operation. Repeating the command does not redo the operation.
Note: If you undo an operation while you have a PDA connected to your PC, the "undone" operation will reappear at the next synchronization. To avoid this, disconnect the PDA, undo the operation, save your .apf file, and reconnect the PDA.
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