20 The work methodology of the Serbian NPM is primarily based on the provisions of the Optional Protocol which set out the mandate of the NPM to make regular visits to institutions where persons deprived of liberty are or may be placed. The Serbian NPM plans to visit all institutions where persons deprived of liberty are placed in the first four years of its work. The NPM methodology recognizes the following types of visits: scheduled, follow-up visits, visits with a specific purpose and ad hoc visits. Visits can be announced and unannounced. After the initial period during which visits were mostly announced, the aim is to make more unannounced visits in the coming months and years. This will ensure more comprehensive insight in the actual situation, which will increase the preventative effect. The methodology of the Serbian NPM is focused on preparation and implementation of unannounced visits to institutions where persons deprived of liberty are or can be placed. After the initial period, when the objective set under the methodology was to make scheduled visits to all institutions, the increase of follow-up visits is planned for the following period. This ensures monitoring of the situation found during scheduled visits, particularly compliance of the competent authorities with recommendations given by the NPM. The methodology of the Serbian NPM is focused on follow-up visits to places of detention. Preparations for visits to a facility involve taking stock of the available information concerning the facility. This is followed by assignment of specific tasks; as a rule, the visit team is divided into four thematic groups; the first one is tasked with observing the conditions of placement (the group for observation of the conditions of placement), the second one is tasked with providing legal protection at the facility (the legal group), the third one deals with correctional work with persons deprived of liberty (the correctional work group), while the fourth group is tasked with reviewing the exercise of health care by inmates (the health care). In order to make the gathering of information during visits more efficient, all team members are provided in advance with the working material (questionnaires, report structure and models of specific sections of the report) which they use as guidance. The NPM teams in charge of visits to institutions where persons deprived of liberty are placed are multi-disciplinary and as a rule include experienced lawyers, a psychiatrist, a forensic physician and a psychologist. Visits take place according to pre-determined stages. The first stage is an interview with the facility’s management, while the second stage is a joint tour of the facility. During the third stage, members of the NPM team’s thematic groups (legal, correctional work and health care) interview the managers of the reference services and examine documentation. The fourth stage involves interviews with persons deprived of liberty, while the fifth stage consists of a brief meeting of all thematic groups, followed by a final interview with the facility’s management in which the team present their preliminary impressions of the visit and the situation they observed. However, these stages are not mandatory and the actual structure of a visit will depend on the type of visit and other circumstances. To enable more efficient and systematic work, questionnaires have been developed for team members to use and fill out during the visits. They also have at their disposal compendiums of quotations from relevant regulations and standards applicable in the specific areas of their work. According to the work methodology, reports are as a rule expected to follow a predetermined structure. However, depending on the type of visit and the type of data collected during a control