Among the 122 Shubnikov point groups, 13 "magnetoelec. types" have been set off. Each "type" except one is described by 1 or several characteristic terms permitted by symmetry in the Taylor expansion of the stored free enthalpy. Linear and 2nd-order magnetoelec. effects and related crystal properties are considered. For all groups, the permitted magnetic and elec. ordering is indicated. The groups permitting "weak ferroelectricity" are obtained by analogy with those permitting "weak ferromagnetism" due to a sym. arrangement of groups and types. Various kinds of domain switching are discussed; piezoelec. and 2nd-order magnetoelec. switching is proposed. Modulation of various coercive fields by magnetoelec. and other means is discussed. The importance of ferroelasticity for magnetoelec. research is pointed out. Several selected topics of examples of compds., representing particular magnetoelec. types, are discussed. Accent is put on ferromagnetoelec. compns. Extended tables on materials of various magnetoelec. types are presented.