  We find exact conditions for the enhancement or suppression of internal
and/or scattered fields and the determination of their spatial distribution or
angular momentum through the combination of simple fields. The incident fields
can be generated by a single monochromatic or broad band light source, or by
several sources, which may also be impurities embedded in the nanoparticle. We
can design the lineshape of a particle introducing very narrow features in its
spectral response.
