The role played by a moment in a combined moment and force excitation has been studied for edge and corner positions of plate-like structures. The moment is expressed as the product of the force and a complex eccentricity. The spatial and temporal variations of its influence on the transmission of active, structural acoustic power is examined in terms of the eccentricity. Two formulations are given, the first of which leads to the eccentricity required for equal or larger contribution of power associated with the moment. The second yields the admissible eccentricity for a neglect of the moment, given some error condition. The point force and moment mobilities as well as the cross-mobility from force to rotational velocity are derived for edge and corner positions. Asymptotic expressions are developed for both the mobilities and the eccentricities. Numerical results are presented covering a wide range of frequencies and spatial positions. As in the case of beam- and frame-like structures [1], it is found that for positions close to discontinuities constraining the translatory motion, moments should be taken into account for all frequencies. The cancellation feature of combined moment and force excitation is analyzed, and it is concluded that it is applicable under the same conditions as those pertaining to beam- and frame-like structures.