Additional validation rules for XML instances including record data components Req 39 Field names shall be unique within a 'DataRecord' component (Req 39) Req 40 Coordinate names shall be unique within a 'Vector' component (Req 40) Req 41, 42, 43 The 'referenceFrame' attribute is forbidden on vector coordinates (Req 41) The 'axisID' attribute is mandatory on vector coordinates (Req 42) The 'referenceFrame' and 'localFrame' attributes shall have different values (Req 43)