Nonlinear oblique interactions between tangential discontinuities (T), rotational discontinuities (A) and fast shocks (Sf) are investigated with the aim of explaining the origin of slow shocks in the solar wind. First, it is shown that the interaction processes SfT and possibly SfA are attractive candidates for explaining the origin of slow shocks consistent with observations, i.e., at the right place in the rising portion of solar wind streams and with large deviations of their normals from the radial direction. Second, heating of the solar wind by damping of fast waves is strongly enhanced by their partial conversion into slow waves. Third, we expect theoretically that the downstream region of flare-produced shock will be considerably richer in fast and slow waves than the upstream region. Fourth, corotating shocks may produce increased numbers of slow shocks just outside 1 AU. Finally, the A moving through the solar wind ensemble of T will be break up into isolated surface segments the edges of which radiate all types of MHD waves.