MySQL's spatial extensions only support bounding box operations
(what MySQL calls minimum bounding rectangles, or MBR). Specifically,
`MySQL does not conform to the OGC standard <http://dev.mysql.com/doc/refman/5.1/en/functions-for-testing-spatial-relations-between-geometric-objects.html>`_:
.. [#fnewkb] *See* `PostGIS EWKB, EWKT and Canonical Forms <http://postgis.refractions.net/documentation/manual-1.5/ch04.html#EWKB_EWKT>`_, PostGIS documentation at Ch. 4.1.2.
.. [#fngeojson] *See* Howard Butler, Martin Daly, Allan Doyle, Tim Schaub, & Christopher Schmidt, `The GeoJSON Format Specification <http://geojson.org/geojson-spec.html>`_, Revision 1.0 (June 16, 2008).
.. [#fndistsphere15] *See* `PostGIS 1.5 documentation <http://postgis.refractions.net/documentation/manual-1.5/ST_Distance_Sphere.html>`_ on ``ST_distance_sphere``.