With the approval of the solicitor's principals, the first and, if appointed, second deputy and the solicitor of the following officers may attend the annual meeting of the principal's respective association with or in place of the solicitor's principals:
(1) Controller.
(2) Sheriff.
(3) Register of wills.
(4) Clerk of orphans' court.
(5) Treasurer.
(6) Prothonotary.
(7) Clerk of courts.
(8) Recorder of deeds.
(9) District attorney.
(10) Public defender.
(11) Coroner.