Warning! You probably shouldn't be using this property.
When this property is true, no views of this document will be updated as this object is changed, and no undo/redo information is kept. When you set the property to false again, you will need to make sure all the views are correct (you may wish to call InvalidateViews). You should also be sure the user and the UndoManager will not be confused by the loss of any undo/redo information while this property was true. Setting this property does not raise any Changed events.