[en] The Stark broadening of isolated ion lines is considered in the electron impact approximation. It is shown by an elementary formulation of the theory that, under certain plasma conditions, situations may arise in complex atoms where a relatively small number of collision-induced transitions predominate in the broadening, and consequently where appreciable variations of spectral line width are obtained within multiplets. Such lines are then particularly suitable for application of the Stark-broadening mechanism as a means of studying atomic structure and collision physics. (author)