[GeoNetwork-users] Problem with where request with geonetwork 2.1

What is exactly the meaning of the 4 types of where request (is,
overlaps, encloses, is fully outsides of) in the advanced mode? I
don't understand the behavior of geonetwork.

I query with lat min : -34.1, lat max : -34.4, long min : 24.1, long max : 24.4

With the "is" mode i obtain 4 results with 3 totally outsides of the
box such as :
lat min : -33.5, lat max : -34.0, long min : 24.0, long max : 24.5

With the "overlaps" mode i don't obtain results

With the "encloses" mode i obtain 9 results with 8 totally outsides of this box

With "is fully outsides of" mode i obtain entire content of my catalog
including a metadata with this box :
lat min : -34.0, lat max : -34.5, long min : 24.0, long max : 24.5

Is this a bug?

Best Regards

Nicolas CASTEL

GMES Applications
THALES ALENIA SPACE Toulouse