Edited sentence: In such cases it makes possible a more representative result than under a rule that a plurality shall elect.Preferential balloting can be used only if expressly authorized in the bylaws.Robert's Rules of Order Newly Revised notes that preferential voting (IRV is the form shown) is especially useful and fair in an election by mail if it is impractical to take more than one ballot, but it is not a substitute for the normal procedure of repeated balloting until a majority is obtained