The dataset on the national spatial reference system (SRS) contains: - data on the national coordinate reference systems (CRS) and height reference systems (HRS), - data on datum transformations between different national coordinate reference systems and between different height reference systems, and - data on hierarchical geographic coordinate grids. The data on the national coordinate/height reference systems contain parameters defining: - national horizontal geodetic datums, including geometrical parameters of the Earth as a planet, the coreresponding reference surface – rotational ellipsoid – and national map projection, and - national height geodetic datum, including physical parameters of the Earth, the height reference surface – (quasi-)geoid – and types of the national height systems. The data on datum transformations contain: - detailed specifications on transformation models with equations and - the corresponding sets of transformation parameters. The data on the national CRSes, HRSes and datum transformations are also supported by the internationally standardized descriptions with unique codes within the EPSG Geodetic Parameter Dataset. Geographical coordinate grids are also available as graphical layers in the Shape format (SHP-files).