65.Under this section the Chief Constable will require each member of the police force to inform him of any “notifiable membership” he believes he has.  A notifiable membership is defined as membership of an organisation which might reasonably be regarded as affecting a police officer’s ability to discharge his duties effectively and impartially (subsection (1)). The Chief Constable may provide guidance to police officers on notifiable memberships, after consulting the Board, the Secretary of State and the Northern Ireland Human Rights Commission.
66.The section places safeguards on the handling and disclosure of information provided to the Chief Constable.  Subsection (10) provides for an offence of wrongful disclosure.  Information will be made available, on request, to the Police Ombudsman and statistical information must be published by the Chief Constable in his annual report.
Commentary Part Vi: the Police Section 51: Notifiable Memberships