Bjorn, you right sampleserver2.arcgisonline.com/ (version 9.3)... returns fault.ArcGIS Server REST API -> Using Spatial References: The REST API supports only well-known ID's.
This JSON code is not WKID, but it is WKT of ESPG::1314:{"wkt":"PROJCS[\"OSGB 1936 / British National Grid\",GEOGCS[\"OSGB36\",DATUM[\"OSGB36\",SPHEROID[\"Airy 1830\",6377563.396,299.3249646,AUTHORITY[\"EPSG\",\"7001\"]],TOWGS84[446.448,-125.157,542.06,0.1502,0.247,0.8421,-20.4894],AUTHORITY[\"EPSG\",\"6277\"]],PRIMEM[\"Greenwich\",0.0,AUTHORITY[\"EPSG\",\"8901\"]],UNIT[\"degree\",0.017453292519943295],AXIS[\"Geodetic latitude\",NORTH],AXIS[\"Geodetic longitude\",EAST],AUTHORITY[\"EPSG\",\"4277\"]],PROJECTION[\"Transverse_Mercator\",AUTHORITY[\"EPSG\",\"9807\"]],PARAMETER[\"central_meridian\",-2.0],PARAMETER[\"latitude_of_origin\",49.0],PARAMETER[\"scale_factor\",0.9996012717],PARAMETER[\"false_easting\",400000.0],PARAMETER[\"false_northing\",-100000.0],UNIT[\"m\",1.0],AXIS[\"Easting\",EAST],AXIS[\"Northing\",NORTH],AUTHORITY[\"EPSG\",\"27700\"]]"}
Question: is the projection in attached screenshot correct?