Parliamentary Privilege Act 1885

Any such order to the Controller of Prisons or any gaoler under section two shall be notified to such Controller of Prisons or gaoler by a summons under the hand of the President or Speaker, as the case may be; and in any such summons shall be stated the name of the prisoner required to attend, and the time and place when and where such prisoner is to attend; and such summons shall be served on such Controller of Prisons or gaoler, either personally or by leaving the same with some person for him at his office.