Williams Castillo is a professional software engineer by trade and stamp collector at heart. A collector since the age of nine, today he has particularly expert knowledge of early Venezuelan stamps up to 1903.An avid student of Venezuelan history as well, he has managed to combine all of these areas of knowledge to the benefit of Venezuelan philately.A frequent writer for the Asociación Filatélica de Caracas (ASOFILCA), he has focused on the study of counterfeits prioritizing his readers; insisting on reaching out to them with invaluable, easy-to-digest information on how they too can detect forgeries.He has also been able to help give meaning to several of our series on unearthing old secrets, aimed at exposing false truths. Among them, the enigmatic 'Tiritas de Coro a La Vela', the unfortunate series on 'Los Godos', the intriguing 'Libranzas', the 'Sellos Numerados', the 'Timbres de Minas', and many more.In this work, his first book, Williams aims to present a practical tool to help bring his favorite series closer to philatelists the world over, giving them access to information previously known only to the very few specialists of these series −the so-called ESCUELAS.