-- Name -- surface type value -- Definition -- Enumeration type which determines the elevation surface with regard to its relative adherence to the Earth's bare surface. -- Description -- EXAMPLE DTM and DSM.
-- Name -- elevation property type value -- Definition -- Enumeration type which determines the elevation property which has been measured or calculated. -- Description -- NOTE 1 An elevation property is a vertically-constrained dimensional property of an element consisting of an absolute measure referenced to a well-defined surface which is commonly taken as origin (geoid, water level, etc.). NOTE 2 It does not include relative elevations of the element referenced to other spatial objects. EXAMPLE Height, depth.