The SDM supports operations on three different map types: LLDG, NEMR, and NRMR. These designations refer to the type of coordinate system the map employs. They have the following meanings:

LLDG - geodetic coordinate system characterized by an ellipsoid only.

NEMR - projected coordinate system characterized by an ellipsoid and map projection.

NRMR - a coordinate system that is not registered to the surface of the Earth.

Since the NRMR coordinates are not related to the surface of the Earth, they have no relationship to any other coordinate system and thus can not be transformed. In particular, the Exchange Coordinate System cannot be used when supplying or obtaining coordinates on this type of map.