Specifies the amount of horizontal space between vertical gridlines.
This element contains a value that sets the horizontal distance between gridlines in points. If this element is not specified, the horizontal space between gridlines is 9.35 pt, the default value.
DisplayHorizontalDrawingGridEvery, DisplayVerticalDrawingGridEvery, DrawingGridHorizontalOrigin, DrawingGridVerticalOrigin, DrawingGridVerticalSpacing, UseMarginsForDrawingGridOrigin
See the example in the DisplayVerticalDrawingGridEvery element topic.