249. For the purposes of this report, and on a general basis, medium-term For the purpose of this detention or imprisonment is considered to be those instances in which people report, these centres are are detained for no more than two months. The most typical circumstances under this heading are the detention of foreign nationals and military arrest for a serious misdemeanour, which as an exception and through the accumulation of where individuals may be detained for up to two months at the most disciplinary measures may extend to a four-month custodial sentence. In both cases, we are dealing with custodial sentences based on administrative procedure. Of the 17 centres of this nature operating in Spain in 2010, an inspection visit has been organised to 12 establishments, belonging to 11 centres. I. Detention centres for foreign nationals 250. Detention centres for foreign nationals (CIEs) are public establishments of Public establishments of a a non-penitentiary nature run by the National Police Force, which provide non-penitentiary nature temporary custody for a maximum period of 60 days, subject to the control and authorisation of the courts, of foreign nationals undergoing proceedings for their expulsion (solely for the reasons provided for in art. 62.1 of PGA 4/2000) on run by the CNP. The detention measure is of a precautionary and instrumental nature, and repatriation. The detention measure is of a precautionary and instrumental has to suitably serve the nature; in other words, it is designed to ensure the successful repatriation of the purpose for which it has foreign national that may eventually be ordered. Accordingly, there is a need to been designed monitor the percentage of repatriations made over the total number of foreign nationals subject to detention to verify that this measure, the most rigorous provided for by legislation on foreign nationals, suitably serves the purpose for which it has been designed. Furthermore, detention should be unilaterally terminated immediately by the authorities hearing the proceedings as soon as it is aware that the repatriation cannot be ordered for any reason whatsoever. It likewise befalls the legal authority to establish the specific period of detention with the aforementioned limit, which is final. The organisation and operation of the CIE, as well as the requirements for being Their organisation and sent there, are governed by Public General Act 4/2000, of 11 January, on the rights operation are governed by and freedoms of foreign nationals in Spain and their social integration, in the draft provided by Public General Act 2/2009, of 11 December, to articles 62, 62.2, 62.3, 62.4, 62.5 and 62.6. During the period covered by this report, the regulatory development of these provisions is to be found in articles 153 to 155 of the Public General Act 4/2000, in the draft provided by Public General Act 2/2009 to arts. 62, 62.2, 62.3, 62.4, 62.5 and 62.6 Regulations approved by Royal Decree 2393/2004, of 30 December and, regarding those matters that do not contradict the preceding rules, in the Ministerial Order of 22 February 1999, on the rules for the internal regime and operation of Internment centres for foreign nationals. The aforementioned Ministerial Order was partially revoked by the Supreme Court of Appeal for Administrative Decisions (Sala de lo Contencioso-Administrativo del Tribunal Supremo), in a THE OMBUDSMAN OF SPAIN 111