GIS registration or geographic control points representing known locations on the earth?s surface —note 1. tics allow all features to be recorded in a common coordinate system, e.g., Universal Transverse Mercator (UTM) meters or State Plane feet —note 2. tics are used to register map sheets when they are mounted on a digitizer, and to transform the coordinates, e.g., from digitizer units (in)to UTM (m) —see root mean square error This definition last updated 10/01/2008