The proceedings of the Los Angeles Caltech-UCLA ‘Cabal Seminar’ were originally published in the 1970s and 1980s. Wadge Degrees and Projective Ordinals is the second of a series of four books collecting the seminal papers from the original volumes together with extensive unpublished material, new papers on related topics and discussion of research developments since the publication of the original volumes. Focusing on the subjects of ‘Wadge Degrees and Pointclasses’ (Part III) and ‘Projective Ordinals’ (Part IV), each of the two sections is preceded by an introductory survey putting the papers into present context. These four volumes will be a necessary part of the book collection of every set theorist.