This volume of the Handbook is the second of a two-volume set of reviews devoted to the rare-earth-based high-temperature oxide superconductors (commonly known as hiTc superconductors). In volume 31 there are ten chapters to complement the eight which appeared in print as volume 30 at the end of 2000 on the same topic. These ten chapters are concerned with the electronic structure and various chemical, physical and optical properties of the hiTc oxides. The first chapter is an extensive review of oxygen nonstoichiometry and lattice effects in Yba2Cu3Ox (YBCO). The next chapter concentrates on flux pinning effect which result in high critical current densities even at high temperatures and in high magnetic fields. The magnetoresistance and Hall effect in both normal and superconducting states of the cuprate superconductors are reviewed in chapter three. The following two chapters are devoted to neutron scattering studies. Chapter six reviews some aspects of the low-temperature heat capacity of the ceramic oxide superconductors. The next three chapters are concerned with various spectroscopies - photoemission, infrared and Raman. Finally the tunneling spectra of the cuprate superconductors and the characterization of these materials by scanning tunneling microscopy are discussed in chapter ten.