European Datum 1950(ED50) is the de facto and de jure geographic coordinate reference system for petroleum industry licencing and operation on the Norwegian continental shelf. The basic input data to this wms service is defined in this Datum, transformations to Euref89 (WGS84) is done on the fly in the server. As the oficially agreed transformations is rather complex, we have choosen a seven parameter vector which gives the smallest overall error |dX| < 1.8m |dY|< 1.7m South of 62 deg N and |dX|< 6.0m |dY|< 2.6m north of 62 deg N.