Volume III/27 deals with magnetic properties of non-metallic inorganic compounds based on transition metal elements such as pnictides, chalcogenides, halides, borates, silicates and phosphates. Subvolume 27B covers the magnetic and related properties of lanthanide pnictides and chalcogenides (except oxides). During the last decades considerable progress in the research of these families of substances has been made. The data have been compiled in several parts. Parts B1 (Monopnictides) and B2 (Monochalcogenides) were published in 1998, the present Part B3 covers the binary polypnictides and polychalcogenides. Part B4 will deal with ternary pnictides.