The property baseSurface references or contains the base surface. The property baseSurface either references the base surface via the XLink-attributes or contains the surface element. A surface element is any element which is substitutable for gml:AbstractSurface. The base surface has positive orientation.
<element name="baseSurface" type="gml:SurfacePropertyType"><annotation><documentation>The property baseSurface references or contains the base surface. The property baseSurface either references the base surface via the XLink-attributes or contains the surface element. A surface element is any element which is substitutable for gml:AbstractSurface. The base surface has positive orientation.</documentation></annotation></element>