18. (1) A public body that was not a signatory to a data-sharing agreement on its date of execution may accede to the agreement by executing an accession agreement to the data-sharing agreement.

(2) An accession agreement referred to in subsection (1) shall be executed, on behalf of the public bodies who were parties to the data-sharing agreement concerned immediately prior to the execution of the accession agreement, by the lead agency specified in that data-sharing agreement in accordance with section 21(1).

(3) A lead agency specified in a data-sharing agreement in accordance with section 21(1) shall notify the Board prior to executing an accession agreement to that data-sharing agreement.