28 C.F.R. § 522.30 Purpose and scope.
When the court orders or recommends an unescorted commitment to a Bureau of Prisons institution, the Bureau of Prisons authorizes the commitment and designates the institution for service of sentence. The Bureau of Prisons also authorizes furlough transfers of inmates between Bureau of Prisons institutions or to nonfederal institutions in appropriate circumstances in accordance with 18 U.S.C. 3622 or 4082, and within the guidelines of the Bureau of Prisons policy on furloughs, which allows inmates to travel unescorted and to report voluntarily to an assigned institution.