"2008-11-19" . . "DataSets/DataSet/Units/Unit/Gathering/SiteCoordinateSets/SiteCoordinates/CoordinatesLatLon/SpatialDatum" . "recommended" . "Examples: \"EPSG:4326\", \"WGS84\", \"NAD27\", \"Campo Inchauspe\", \"European 1950\", \"Clarke 1866\""@en . . "2009-07-06" . "The ellipsoid, geodetic datum, or spatial reference system (SRS) upon which the geographic coordinates given in decimalLatitude and decimalLongitude as based. Recommended best practice is use the EPSG code as a controlled vocabulary to provide an SRS, if known. Otherwise use a controlled vocabulary for the name or code of the geodetic datum, if known. Otherwise use a controlled vocabulary for the name or code of the ellipsoid, if known. If none of these is known, use the value \"unknown\"."@en . "Geodetic Datum"@en . . . .