OptionalmaxMax undo levels.
OptionalskipThe names of the undo commands to skip. Available built-in command names are: "Open", "Close", "FrameIndex", "Zoom", "Rotation", "Flip", "StartAnimation", "StopAnimation". Note that the "Open"/"Close" and "StartAnimation"/"StopAnimation" commands are paired - if one command is skipped, the other command will also be skipped.
Undo storage options.