Many times there are subjects which demand further explanations and guid­ ance written about them. Such is the case with SGML, the Standard Generalized Markup Language; and ISO Standard published in October, 1986 under the number 8879. There have been many conferences given on this topic, world-wide, as the interest in SGML exists in Europe, the US, Australia and Japan. This book is the first which contains information not only on ISO 8879 itself, but many helpful hints and ideas on developing SGML, applications and discussions of the current software written to be conforming to the ISO standard. 'Ibis book is critical for any end-user and application developer to understand the many issues neccessary to develop SGML implementations (software selection is one of the topics discussed) and SGML applications. A number of examples of the applications of SGML in various situations are discussed and one can expect that the book will stimulate further discussion of these. This book is a practical guide to various components of the language and the author's experience in development and worldng with SGML in his position as leader of the text processing section at CERN ensures that the guidance is based on practical first-hand experience at an installation with a large number of end-users of very varied experience.