- 50 The CPT recommends that all detained irregular migrants be provided with full information, in a language they understand, on their legal situation and be informed in advance of their right to be represented by a lawyer at the detention review hearings before the administrative courts and of their right to challenge the detention measure in deportation cases. 89. If, at the end of their period of detention, detained persons could not be deported/returned, they were provided with a laissez-passer paper valid from seven to 30 days, during which they were supposed to leave the territory of Greece; failure to comply with leaving the country meant they were liable to being detained for a further period of three months renewable up to 18 months. The CPT does not fully understand the rationale of the very short period provided by the laissez-passer as one could not expect the irregular migrant to be able to leave the country within a period of seven to 30 days, if the Greek State was unable to effect his return in a period of one year or more. The CPT would appreciate the observations of the Greek authorities on this matter. 90. It is in the interest of both irregular migrants and staff that there be clear house rules for all detention facilities, and copies of the rules should be made available in a suitable range of languages. This was not the case at the time of the 2013 visit. The only provisions that currently exist are the Internal Operating Regulations for Alien Detention Facility Guarding Services of 10 March 2013, which would need to be both substantially reviewed and supplemented to serve as house rules. The house rules should primarily be informative in nature and address the widest range of issues, rights and duties which are relevant to daily life in detention. They should, inter alia, contain disciplinary procedures and provide detainees with the right to be heard on the subject of violations that they are alleged to have committed, and to appeal to an independent authority against any sanctions imposed. Without such rules, there is a risk of an unofficial (and uncontrolled) disciplinary system developing. For example, in Xanthi police station, the delegation met a man who had been transferred from the Xanthi pre-departure centre because he was considered disruptive to other detainees. He had been held for 46 days on his own in the police cell (see paragraph 45 above).54 In the light of the above remarks, the CPT recommends that house rules be adopted for each pre-departure centre and special holding facility, which should be clearly posted in the accommodation areas in languages understood by the detainee population. 91. The CPT considers contacts with the outside world to be essential for the well-being of detained persons; consequently, detained irregular migrants should be afforded every opportunity to maintain such contacts. In all the centres visited, it was possible for detained persons to receive visitors; however, there was no common approach. 54 The Internal Operating Regulations contain no provisions on how to deal with refractory and/or difficult detainees other than to permit the director of a centre to introduce restrictive measures; see Article 23.2.