This work is not just a reprint of the 1973 edition of the Catalogo. This edition takes a deeper look into the Claveria decree on surnames as well as present for the very first time the fully sanitized and alphabetically-arranged list of the Catalogo.It is the goal of this work to answer some, if not all, of the questions and conclusions posed by Domingo Abella in 1973 edition of the Catalogo. Furthermore, a discussion on Narciso Claveria, his life, and his accomplishments will also be made in this book because, whether we like it or not, Claveria's Renovacion de Apellidos remains one of the most influential decrees from the Spanish era whose effects are still felt to this very day. To understand the decree, one must understand Claveria and his times.