Are MKMapView GEOErrorDomain codes documented anywhere?

Apple provides a method in MKMapViewDelegate for handling map view errors.

- (void)mapViewDidFailLoadingMap:(MKMapView *)mapView 
                   withError:(NSError *)error;

A few of our users complained about map tiles not loading, so we added tracking in Crashlytics. We're seeing a bunch of different error codes all falling under the GEOErrorDomain domain.

Some of the codes we're seeing: -204, -218, -209, -7, -602

The only problem is that these errors have no localized descriptions recorded by Crashlytics, and I can't seem to find documentation on these anywhere. Are these errors documented anywhere?