Increasing use of the DDC in the German-speaking regions leads to a considerable increase in the demand for information and teaching material on this classification system in Library training and practice. The German translation of the DDC instruction book offers both students and all those working practically or researching with the DDC classification, an extensive introduction to the theoretical basics of the classification, supplemented by professional aspects and many individual examples. The use of tables and the notation synthesis are explained in detail, and clarified with practical exercises. This textbook is thus also well suited for individual studies, offering numerous possibilities to check and repeat what has been learned. For the teacher, there are notes on structuring leasons and preparing teaching material and tests.