Selection.Subtract Method (Visio)
Subtracts the areas that overlap the selected shape.
Version Added: Visio 4.0
expression A variable that represents a Selection object.
Calling the Subtract method is equivalent to clicking Subtract in the Microsoft Visio user interface (click Operations in the Shape Design group on the Developer tab). The first selected shape is the one that will have the other selected shapes subtracted from it. The other shapes will be deleted and no shapes are selected when the operation is complete.