56.Before the powers under section 21 become exercisable, the senior officer who gave the authorisation is required to ensure that an authorisation notice is published in a newspaper circulating in the relevant locality and that it is displayed in some conspicuous place or places within the relevant locality.
57.Subsection (2) sets out what must be included in an authorisation notice: a statement that the authorisation has been given and specification of the area affected and the period it will last (and any specified times within that period).
58.Subsection (3) makes provision for withdrawal of the authorisation (for example, if the police are satisfied that it is no longer necessary to prevent the occurrence of disorder or serious nuisance). Subsection (4) requires the police officer to consult the relevant local authority or authorities about the proposed withdrawal. Subsections (5) and (6) set out that the withdrawal of an authorisation shall not affect the exercise of any power which occurred before the withdrawal and that the giving or withdrawal of an authorisation shall not prevent the giving of a further authorisation in respect of a locality to which the earlier authorisation relates.