I have noticed that the point3dOpt and point3dReq simple types are exactly the same. Shouldn't point3dReq have <xs:minLength value="3"/>. Furthermore the GPSAntennaDetails have both normal equipment details information and positional information like latitude, longitude and altitude. Is it not better in the long term to separate these? Also there are some mistakes in the schema change document. It is not <InstrumentSetup>.<Corrections> were <TestObservation> has been added, but <ControlChecks>. Also the latest changes in the face <F> element has not yet been reflected in the documentation. Regards Eilert Schwarting Schwarting Land Surveyors Omeg Allee Erf 1504 P.O. Box 1111 Tsumeb Namibia Tel +264 (67) 220250 Fax +264 (67) 220003 Cell 0811241890