MONITORING PLACES OF DETENTION : A PRACTICAL GUIDE 18 The guide is not tailored to any specific mechanism, nor to any particular country or region. It aims to be valid for a broad and universal public. Scope of the guide The guide is intended to deal with monitoring in any place where persons are deprived of their liberty. In practice, however, it focuses mainly on prisons and, in a more limited way, on police stations. Monitoring specific places such as psychiatric institutions, centres for juveniles or detained foreign nationals requires a specific approach, although some of the general concepts are applicable. Specific categories of vulnerable detainees, such as women, children, minorities and foreign migrants, are not considered in a separate chapter but, where possible, are included throughout the guide under different topics. The guide is structured as follows: The first chapter contains a general introduction on the importance of monitoring conditions of detention. The second chapter briefly sets out the existing international and domestic mechanisms, and makes special reference to the features of national preventive mechanisms as set out by the OPCAT. The third chapter is of a more operational nature, describing how to conduct a visit from preparation to follow-up. The last chapter sets out, theme by theme, the aspects of detention that should be considered during a visit and comments upon the corresponding provisions in international standards. Definition of key terms: Monitoring places of detention Monitoring places of detention describes the process, over time, of regular examination, through onsite visits, of all aspects of detention. The examination can involve all or certain categories of detainees (see below) held in one or more places of detention (see below).