True if spatial reference has a vertical coordinate system set; false otherwise. A spatial reference can optionally include a definition for a vertical coordinate system (VCS), which can be used to interpret the z-values of a geometry. A VCS defines linear units of measure, the origin of z-values, and whether z-values are "positive up" (representing heights above a surface) or "positive down" (indicating that values are depths below a surface).
A SpatialReference may have a VCS set, for example by calling the SpatialReference.SpatialReference(Int, Int) constructor. SpatialReference.verticalWkid, SpatialReference.wkText, and SpatialReference.verticalUnit provide more information about the specific VCS set on this instance.
VCSs are used when projecting geometries using a HorizontalVerticalTransformation.