an Entity references as follows:
EPSG Geodetic Parameter Dataset (also EPSG registry) is a public registry of geodetic datums, spatial reference systems, Earth ellipsoids, coordinate transformations and related units of measurement. Originally created by European Petroleum Survey Group (EPSG). Each entity is assigned an EPSG code between 1024-32767, along with a standard machine-readable well-known text (WKT) representation. The dataset is actively maintained by the IOGP Geomatics Committee.