The Stokes parameters of scattered light are given by the matrix equation \[(s_{0},s_{1},s_{2},s_{3}) = F\ (s_{0}^{0},s_{1}^{0},s_{2}^{0},s_{3}^{0})\] where the 4, 4 scattering matrix F is comprised of 16 scattering matrix elements. These matrix elements, which may originate in theory or experiment, provide a complete description of the scattered radiation in terms of the incident radiation.