Basic control point networks covering the whole nation are established according to classes of different grades (or named orders) and precision standards. These basic control points are set up with various types of stakes or marks on the ground and surveyed as the bases for all kinds of surveying works to achieve diverse human cultural developments. Generally, they are classified into three orders named First Order, Second Order, and Third Order. Currently, there are totally 4,435 permanent points nationwide including the first/second/third order satellite control points and the first order bench marks. The NLSC has made a regular mechanism of control points inspection, management, and maintenance to keep the national coordinate system well, usable and reliable.