In psychiatric practice, classification systems are useful to improve communication among mental health professionals and researchers and to establish widely agreed descriptions of mental disorders, and should not be considered textbooks of psychopathology. ...classification systems offer a framework for education on the most common clinical features of mental disorders through the organization of disorders into discrete diagnostic categories 34. ...diagnostic systems facilitate the identification and management of mental disorders in clinical settings and have a significant predictive power 5. ...the revision of the ICD-11 represents the biggest global, multidisciplinary, and participative process of revision of a classification system for mental disorders which has ever been implemented 9. In order to adapt the classification system to the local countries’ laws, policies, health systems, and infrastructures, several multilevel actions have been subsequently implemented. ...since education of health care professionals represents one of the most essential steps for the implementation and the dissemination of the new classification system in routine care, the WHO International Advisory Group led by G. M. Reed has organized training courses for professionals on the use of the ICD-11 chapter on mental, behavioral, and neurodevelopmental disorders and the relevant CDDG.