(1)For the purposes of this Act an organisation is proscribed if—
(a)it is listed in Schedule 2, or
(b)it operates under the same name as an organisation listed in that Schedule.
(2)Subsection (1)(b) shall not apply in relation to an organisation listed in Schedule 2 if its entry is the subject of a note in that Schedule.
(3)The Secretary of State may by order—
(a)add an organisation to Schedule 2;
(b)remove an organisation from that Schedule;
(c)amend that Schedule in some other way.
(4)The Secretary of State may exercise his power under subsection (3)(a) in respect of an organisation only if he believes that it is concerned in terrorism.
(5)For the purposes of subsection (4) an organisation is concerned in terrorism if it—
(a)commits or participates in acts of terrorism,
(b)prepares for terrorism,
(c)promotes or encourages terrorism, or
(d)is otherwise concerned in terrorism.