[6]Deprivation of liberty is defined in article 4 (2) of the Optional Protocol to the Convention against Torture and other Cruel, Inhuman or Degrading Treatment or Punishment as “any form of detention or imprisonment or the placement of a person in a public or private custodial setting which that person is not permitted to leave at will by order of any judicial, administrative or other authority”. Rule 11 of the United Nations Rules for the Protection of Juveniles Deprived of their Liberty states: “For the purposes of the Rules, the following definitions should apply: … (b) The deprivation of liberty means any form of detention or imprisonment or the placement of a person in a public or private custodial setting, from which this person is not permitted to leave at will, by order of any judicial, administrative or other public authority.”