In most centres, measures are subject to entry in the detention register in accordance with the instructions given by the Minister for Immigration, Integration, National Identity and Development Solidarity in the circular of 14th June 2010, which followed-up numerous recommendations made in inspection reports issued by the Contrôleur général. On the other hand, contrary to the instructions contained in this circular, the reasons for placing persons in solitary confinement are not always given. The State Prosecutor’s Office is only informed of these measures when they have lasted for a sufficiently long time, without this period of time being subject to a more precise definition. Placements in solitary confinement may also be entered in the daybook kept by staff working in CRAs, but notes of this kind are often difficult to find. Sometimes, such registers do not exist and the IT daybook serves as the only substitute for entries in a detention register. These difficulties of traceability render assessment of the lengths of time for which detainees are placed in solitary confinement a complex task. The information given is often purely declaratory, mentioning a time of between two and three hours. However, periods of up to seven days have been ascertained. It is rare to find CRAs in which a specific procedure exists, fixed by a memorandum and recalling the exceptional character of physical exclusion, which has to be justified by disturbance of public order or threat to the safety of other detained foreigners. There are different reasons for placement in exclusion: insults and threats, involvement in fights between detainees, feigned sickness etc. In certain CRAs inspected it was also noted that exclusion may be used as a way of dealing with concerns related to health: when detainees show behavioural disorders, when they have attempted suicide, for example. Indeed, behavioural disorders and disturbance of public order are the two reasons most frequently cited in order to justify physical exclusion. Although the ministerial circular of 14th June 2010 specifies that “this procedure [of placement in solitary confinement or exclusion] should not have any disciplinary character and should in no way worsen the conditions of detention of illegal immigrants”, it is reported that throughout the whole period of such confinement, meals are not eaten in common with others, visits are suspended and mobile telephones are, if necessary, confiscated. Nevertheless, in one centre an internal memorandum indicates that: “use of means of physical restraint during exclusion shall be strictly limited in time, in the presence of a very agitated detainee and pending a different method of dealing with them (medical for example)”. According to the minister in charge of immigration, the legal basis of placement in exclusion is drawn from article 17 of the standard regulation worked out in application of article R.553-4 of the Code for Entry and Residence of Foreigners and Right of Asylum. This article only resolves the question of the legal basis of standard regulations and not that of thei r content. It therefore leaves the question of the disciplinary regime to be put in place unresolved. Provision needs to be made for the latter in the Code for Entry and Residence of Foreigners and Right of Asylum, as the Contrôleur général has been requesting for several years. It is on this tenuous basis that the rules and regulations of detention centres, which include provisions concerning security and discipline, are approved by prefects. Like all directors of institutions, heads of CRAs have police powers. In this capacity, they may carry out any police measures or have such measures carried out, in order to maintain or reestablish internal order. However, these measures can only be implemented under the control of a judge. 107