(b) (2) the Committee. The Permanent Secretary may consult a technical advisory committee set up by him, or any public department, on a notice. 13. Variation notice (1) Any person affected by a notice, may apply to the Permanent secretary for an amendment of the notice. (2) The Permanent Secretary, on his own initiative, or on application, may amend a notice by causing to be served on the person affected a variation notice. (3) (4) A variation notice shall – (a) refer to the notice which is amended; (b) specify the amendment to the notice; (c) where necessary, vary the date specified in the notice. A variation notice shall supersede the notice to which it refers to the extent of the amendment. 14. Service of notice (1) A notice issued under this Act shall be served – (a) personally on the person affected, or in the case of a body corporate, at its registered address; or (b) by registered post sent to, or by leaving a copy at, the last known address of the person affected.