  It is proposed that the observation of orbital ordering in manganite
materials should be possible at the L_II and L_III edges of manganese using
X-ray resonant scattering. If performed, dipole selection rules would make the
measurements much more direct than the disputed observations at the manganese K
edge. They would yield specific information about the type and mechanism of the
ordering not available at the K edge, as well as permitting the effects of
orbital ordering and Jahn-Teller ordering to be detected and distinguished from
one another. Predictions are presented based on atomic multiplet calculations,
indicating distinctive dependence on energy, as well as on polarization and on
the azimuthal angle around the scattering vector.

Condensed Matter