These Rules amend the Prison Rules 1999 (S.I. 1999/728) to create a new rule 46A to make provision for separation centres. The new rule confers on the Secretary of State a discretion to direct that prisoners are placed in such a centre within a prison. The new rule sets out the grounds which must be satisfied prior to the Secretary of State making such a direction, namely: national security, preventing terrorism offences, preventing the dissemination of views that might encourage such offences, and preventing the use of particular views or beliefs to undermine good order and discipline.