UN documents (g) Effective domestic mechanisms of oversight, including complaints mechanisms, form an essential part of the apparatus of prevention. These mechanisms will take a variety of forms and operate at many levels. Some will be internal to the agencies involved, others will provide external scrutiny from within the apparatus of government, whilst others will provide wholly independent scrutiny, the latter to include the National Preventive Mechanism (NPM) to be established in accordance with the provisions of the Optional Protocol. (h) Torture and ill-treatment are more easily prevented if the system of detention is open to scrutiny. NPMs, together with national human rights institutions and ombudsman’s offices, play a key role in ensuring that such scrutiny takes place. This is supported and complemented by civil society, which also plays an important role in ensuring transparency and accountability by monitoring places of detention, examining the treatment of detainees and by providing services to meet their needs. Further complementary scrutiny is provided by judicial oversight. In combination, the NPM, civil society and the apparatus of judicial oversight provide essential and mutually reinforcing means of prevention. (i) There should be no exclusivity in the preventive endeavour. Prevention is a multifaceted and interdisciplinary endeavour. It must be informed by the knowledge and experience of those from a wide range of backgrounds – e.g. legal, medical, educational, religious, political, policing and the detention system. (j) Although all those in detention form a vulnerable group, some groups suffer particular vulnerability, such as women, juveniles, members of minority groups, foreign nationals, persons with disabilities, and persons with acute medical or psychological dependencies or conditions. Expertise in relation to all such vulnerabilities is needed in order to lessen the likelihood of ill-treatment. National Preventive Mechanism in the Republic of Slovenia under the Optional Protocol to the UN Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment 157