The Visiting Forces and International Headquarters (Application of Law) Order 1999

5.  The provisions of any enactment, or of any instrument having effect under an enactment, with respect to the treatment of persons detained in prisons or other establishments mentioned in the foregoing provisions of this Schedule (including any provisions relating to unsoundness of mind) shall apply—

(a) in relation to any person detained in pursuance of this Schedule in a civil prison, as if he were a person sentenced by a court of the United Kingdom to imprisonment for the like term as the term of the sentence of the service court;

(b) in relation to a person sentenced by a service court to any form of imprisonment and detained as aforesaid in any naval, military or air-force establishment, as if he were a person sentenced by a court-martial under the Naval Discipline Act 1957, the Army Act 1955 or the Air Force Act 1955, as the case may be, to imprisonment for the same term as the term of the sentence of the service court;

(c) in relation to a person sentenced by a service court to any other form of custody and detained as aforesaid in any naval, military or air-force establishment, as if he were a person sentenced by a court-martial under the Naval Discipline Act 1957, the Army Act 1955 or the Air Force Act 1955, as the case may be, to detention for the same term as the term of the sentence of the service court.