UTM or Universal Transverse Mercator is an older system for specifying a global position on the planet similar to the Latitude and Longitude except the values are called Northing and Easting and requires a Zone.
In Norway, this UTM system is a standard way for governmental organizations to define location. For example, Ruter, the public transit agency, uses it in their public transit APIs. This library will tranlate between a UTM coordinate and the Lat/Long coordinates that are more commonly used on modern platforms like iOS.
UTMCoordinates coordinates;
coordinates.gridZone = 32;
coordinates.northing = 6643010;
coordinates.easting = 598430;
coordinates.hemisphere = kUTMHemisphereNorthern;
CLLocationCoordinate2D groenland = [GeodeticUTMConverter UTMCoordinatesToLatitudeAndLongitude:coordinates];
If you want to supply your own Datum, then
GeodeticUTMConverter *converter = [[GeodeticUTMConverter alloc] initWithDatum:UTMDatumMake(6378137, 6356752.3142)];