The theologian Paul Avis, in his handbook for those becoming bishops in the Anglican Communion, makes scarcely any reference throughout the course of the treatise to any distinction between a diocesan and a non-diocesan bishop. At one level this is refreshing, eschewing as it does any notion of a hierarchy within the order of bishops. However, on another level it is somewhat odd, for so much of the episcopal polity and praxis articulated throughout assumes the reader is ‘becoming’ a diocesan bishop, and is, consequently, at times irrelevant to those who are ‘becoming’ a bishop in an assisting role.