The Northern Ireland (Sentences) Act 1998 (Specified Organisations) Order 2001
Under section 3 of the Northern Ireland (Sentences) Act 1998, the Secretary of State must specify an organisation if he believes that it is concerned with terrorism connected with the affairs of Northern Ireland, or in promoting or encouraging it, and that it has not established or is not maintaining a complete and unequivocal ceasefire. The Secretary of State is obliged to review the list of specified organisations from time to time.