vi Preface to the Second Revised Edition of the “Human Dignity and Public Security” Department at the BIM, based upon our joint research and broad practical experience. Manfred Nowak, Moritz Birk and Giuliana Monina serve as joint editors, but the different Articles of the Convention against Torture (CAT) and its Optional Protocol (OPCAT) are written under the individual responsibility of a variety of highly experienced authors, who are either current or former staff of the Ludwig Boltzmann Institute of Human Rights: Moritz Birk, Giuliana Monina, Nora Katona, Margit Ammer, Kerstin Buchinger, Stephanie Krisper, Johanna Lober, Roland Schmidt, Andrea Schüchner, and Gerrit Zach. The ten-​year interval since the first edition has seen several important developments in the field. There has been a considerable change in the ratification status of both the Convention and its Optional Protocol, with 162 States having ratified the CAT and 88 States having ratified the OPCAT. Since 2008, the CAT Committee has adopted three new General Comments; more than 200 new individual complaints covering all substantial articles; new rules of procedure as well as conducted four new inquiry procedures under Article 20 CAT (in Egypt, Lebanon, Nepal and Brazil). In the framework of the treaty body strengthening process, it has developed various measures aimed at improving the States parties’ compliance with their Convention obligations, above a simplified reporting procedure to guide States parties in their reporting duties; a procedure on follow-​up to concluding observations, individual complaints and inquiry procedure to better monitor the implementation of its recommendations; and a mechanism to prevent, monitor and follow-​up cases of intimidations and reprisals against civil society organizations, human rights defenders, victims and witnesses that engage and cooperate with the Committee. In relation to the Optional Protocol, the first edition of this Commentary was published at a time when the SPT was not yet operational, thus, it relied primarily on the practice of the European Committee for the Prevention of Torture (CPT). The second edition contains a detailed analysis of the initial ten years of work of the SPT taking into account the work of National Preventive Mechanisms (NPMs). To reflect these changes and developments this edition has been substantially revised. As the earlier version, it attempts to be an in-​depth analysis of all substantive, organizational and procedural provisions of the Convention against Torture and its Optional Protocol and wants to ensure that the Commentary continues to serve as a comprehensive guide for researchers and practitioners alike. For that purpose, it was attempted to make the manuscript more user friendly by modifying the original structure merging the practice of the Committee with the analysis of the issues of interpretation, thereby trying to avoid repetitions and providing a more concise analysis. The structural changes and the significant developments in the jurisprudence and practice of the two treaty bodies required considerable revision, re-​organisation and expansion of many Articles. Other Articles, however, required only minor updates and build more strongly on the text of the first edition authored by Manfred Nowak and Elisabeth McArthur (ie Articles 8, 9, 10, 17, 18, 23-​27, 29, and 31-​33 CAT). Moreover, the second edition leaves untouched the thorough analysis of the travaux préparatoires of the Convention and its Optional Protocol in the Commission on Human Rights and its inter-​sessional Working Group already drafted by the authors of the first edition. We wish to express our sincere gratitude to many individuals who provided us with information and advice during our research work, above all Patrice Gilbert from the Office