It has been established that the kinematics of the Voigt transformation, which lacks group structure, is different from that of the Lorentz transformation, and that the apparent kinematic asymmetry of the Voigt coordinate transformations may be understood as a conformally symmetric kinematics. Phenomena such as the kinetic energy of a moving body and the Doppler effect are not quite the same under the conformal Voigt transformation as they are for the usual theory developed with respect to the Lorentz group. Yet (...) the massenergy conservation law under the Voigt coordinate transformations and the mass-energy conservation law under the group of Lorentz transformations are identically the same. (shrink)