Oversight mechanisms The standard questionnaire for evaluating the implementation of the Schengen acquis in a  given Member State contains questions relating to children in detention. They address how to promote the best interests of the child throughout the entire return procedure, including when considering detention; how to address the special needs of vulnerable persons when providing detention conditions inside the territory and at the border; if specialised detention or reception facilities for unaccompanied children are in place; and if alternatives to detention are available.413 The regular announced reviews have covered 12 EU  Member States between 2015 and May  2017. Although the results are restricted, several findings and recommendations relate to the situation of children in detention pending removal. 8.4. Complaint mechanisms Another important tool for protecting human rights is the opportunity to lodge an individual complaint against alleged violations. Effective complaints procedures are a basic safeguard against ill-treatment in detention, the CPT noted. 414 Complaint mechanisms exist at the national as well as at the supra-national level. Broadly speaking, there are two different types of mechanisms: (1) appeals to a court or tribunal entitled to make a binding decision and (2) complaints to other bodies that can issue recommendations. This section deals with the second type of complaint mechanism. At the supra-national level, most of the UN human rights instruments include individual complaint mechanisms but immigration detention cases in Europe seldom use them. The Human Rights Committee has dealt with immigration detention cases from Australia, 415 and the UN Committee Against Torture reviewed the case of migrants intercepted by Spain off the coast of Mauritania.416 An individual complaint mechanism also exists 413 European Commission (2014), Annex to the Commission Implementing Decision establishing a standard questionnaire in accordance with Article 9 of Council Regulation (EU) No 1053/2013 of 7 October 2013 establishing an evaluation and monitoring mechanism to verify the application of the Schengen acquis, C(2014) 4657 final, Brussels, 11 July 2014, Chapter 2 (Return and readmission). 414 Council of Europe, CPT (2015), Juveniles deprived of their liberty under criminal legislation, Extract from the 24th General Report of the CPT, published in 2015, CPT/ Inf(2015)1-part, para. 131. 415 UN, Human Rights Committee, A. v. Australia, 3 April 1997, CCPR/C/59/D/560/1993; C. v. Australia, 28 October 2002, CCPR/C/76/D/900/1999; Saed Shams and Others v. Australia, 20 July 2007, CCPR/C/90/D/1255, 1256, 1259, 1260, 1266, 1268, 1270 and 1288/2004; F.K.A.G. v. Australia, 26 July 2013, CCPR/C/108/D/2094/2011. 416 UN, Committee Against Torture (CAT), J.H.A. v. Spain [Marine I case], 21 November 2008, CAT/C/41/D/323/2007. under the CRC. Optional Protocol No. 3 allows individual children to submit complaints regarding specific violations of their rights under the Convention and its first two optional protocols. Only 12 EU Member States have ratified Optional Protocol No. 3 and seven EU countries have signed but not ratified it as of April 2017. The need for effective complaint mechanisms derives from Article 2 of the ICCPR which states that every person has the right to an effective remedy. The UN Rules for the Protection of Juveniles Deprived of their Liberty (Havana Rules)417 provide that every child “should have the opportunity of making requests or complaints to the director of the detention facility and to his or her authorized representative.”418 They also state that every child should have the right to lodge a complaint with “the central administration, the judicial authority or other proper authorities through approved channels.”419 Independent mechanisms, such as the Ombudsman, should be able to receive and examine children’s complaints.420 Such preventive measures are relevant to prevent all children from violence, abuse of neglect as required by Article 19 of the CRC.421 Most Member States provide internal or external mechanisms, or both. Internal complaint mechanisms take various forms. • In Finland, Hungary and Malta, complaints can be addressed to the Director or Head of the detention facility.422 • Some senior officials can also receive and review complaints, for example the Chancellor of Justice in Estonia.423 • Portugal has a more formal complaint mechanism with a permanent monitoring committee.424 • While important, taken alone, internal complaint mechanisms are not necessarily viewed as effective. 417 UN, General Assembly, Resolution 45/113, United Nations Rules for the protection of juveniles deprived of their liberty, 14 December 1990, A/RES/45/113 (Havana Rules). 418 Ibid., para. 75. 419 Ibid., para. 76. 420 Ibid., para. 77. 421 See UN, Committee on the Rights of the Child (CRC) (2011) General comment No. 13 (2011), the right of the child to freedom from all forms of violence, 18 April 2011, paras. 45ff. 422 Hungary, Act LXXX of 2007 on Asylum (2016) (2007. évi LXXX Törvény a menedékjogról) 1 January 2008, Article 31/G; Finland, Joutseno Detention Unit, 26 February 2016; Malta, Subsidiary Legislation 260.06, Detention Service Regulations, 15 January 2016, Regulation 42. 423 Estonia, Equal Treatment Act (Võrdse kohtlemise seadus), 1 April 2013, Article 16; Estonia, Chancellor of Justice Act (Õiguskantsleri seadus), 1 January 2016, Article 1 and Article 19. 424 Gonçalves, N., Jorge, A., Cabral, H, Bronzin, M., Varela, A., Alves, S., Silva, G., Fernandes, P., Almeida, I., Gil, A., Duarte, F. (2010), Muros que nos separam: Detenção de requerentes de asilo e migrantes irregulares na UE, Prior Velho and Águeda, Paulinas, pp. 79-81. 93