ESSEX PAPER 3: INITIAL GUIDANCE ON THE INTERPRETATION AND IMPLEMENTATION OF THE UN NELSON MANDELA RULES an establishment)’ and pointing out that these procedures should also be accompanied by effective safeguards.279 The Essex group noted that Rule 36 is laying down the only possible purposes for restrictions, i.e. safe custody, secure operation of the prison and a well-ordered community life. The experts considered that more detailed discussion and guidance will be needed with regard to the differentiation between disciplinary sanctions and ‘other restrictions’. Other issues identified as requiring more discussion and practical guidance were the application of Rule 39(3); compensatory measures as described in Rule 38(2); and criteria to assess whether solitary confinement would exacerbate the situation of prisoners with mental or physical disabilities. General principles The Essex group emphasised the means and tools at the disposal of prison administrations in order to avoid and prevent disciplinary infractions in the first place, and pointed out five overarching principles: 1. Restrictions and disciplinary sanctions should not be a first response to problems within prisons – they may only be imposed once steps aimed at preventing conflicts or resolving them through other means have failed (Rule 38(1)). 2. Only such restrictions and disciplinary sanctions as are provided in laws and regulations may be imposed (Rules 37). 3. No restrictions or disciplinary sanctions may involve lowering the general living conditions (Rule 42). 4. Measures need to be necessary and proportionate, and need to be imposed through fair proceedings (Rule 39(1) and (2)). 5. Restrictions or disciplinary sanctions must never amount to torture or other cruel, inhuman or degrading treatment or punishment (Rule 43(1)).280 Principle of legality The Essex group pointed to Rule 37, which enshrines the principle of legality and clarifies that authorisation by law or by regulation is always required to determine:281 •  what conduct constitutes a disciplinary offence and what conduct/situation may prompt ‘other restrictions’ •  types and duration of sanctions/restrictions that may be imposed •  the authority competent to impose such sanctions/restrictions •  any form of involuntary separation from the general prison population (whichever term is used e.g. isolation, segregation, restricted housing or special care units and regardless of whether or not it is applied as a disciplinary sanction or citing order and security reasons). European Committee for the Prevention of Torture and Inhuman or Degrading Treatment or Punishment (CPT), 2nd General Report on the CPT’s activities covering the period 1 January to 31 December 1991, 1992, CPT/Inf (92) 3, para. 55 (CPT 2nd General Report). 279  Rule 47(1) applies this principle specifically to instruments of restraint. 280  Rule 37 reflects Principle 30(1) of the Body of Principles for the Protection of All Persons Under Any Form of Detention or Imprisonment. 281  Penal Reform International and the Essex Human Rights Centre | 78