In volume III/21 a compilation is given of all reported experimental data on superconducting materials from the discovery of this phenomenon. The data presented include not only the superconducting properties related to a given material, but also the full metallurgical and crystallographical characterization. The compilation is not restricted to the superconducting properties, but is extended to other low temperature physical properties, which are explicitly given in a particular column. All substances are arranged alphabetically by the base element, i.e. the element with the highest concentration in an alloy or compound. Only original and critically reviewed experimental data are retained.