  Magnetic diffraction of polarized neutrons by the cubic Laves compound UAl2
in a magnetic field has unveiled weak Bragg spots that are nominally forbidden.
On the one hand, they can be viewed as magnetic analogues of the
basis-forbidden (2, 2, 2) reflection in diamond-type structures that has been
painstakingly and frequently investigated over almost a century. Alternatively,
the pattern of weak intensities can be assigned to Dirac multipoles imbedded in
field-induced magnetic charge. To this end, a published diffraction pattern is
successfully confronted with intensities calculated from the appropriate
magnetic space-group that includes Dirac dipoles (anapoles) to describe the
basis-forbidden magnetic reflections, and conventional (axial) dipole and
octupole multipoles to describe basis-allowed magnetic reflections.
