The preceding chapters have been concerned primarily with explicating the physical features of scattering electromagnetic plane waves from dielectric spheres, particularly for large size parameters. Much of the theoretical development is strongly dependent upon the maximal symmetry of this scenario, as well as upon the idealization of an incident plane wave. Although the spherical target is a good approximation to many of those encountered in important physical problems, there exist many other situations in which departures from sphericity cannot be ignored. Moreover, an infinite plane wave is clearly a fiction, albeit a very useful one, and in reality we have only the approximation of a locally plane wave. In many applications the incident radiation is provided by a tightly focused laser beam that may, but need not, satisfy this criterion. Thus, while the bulk of the work presented here provides a sound basis for understanding the basic scattering problem, there is a large body of physical applications in which one or more of the idealizations inherent in our model may fail to be realized. In this final chapter we shall attempt a brief and necessarily incomplete survey of some of the ways in which the fundamental model and its analysis must be altered in these situations. For the most part derivations and extensive mathematical expressions are omitted.