9A Commission shall have power to act notwithstanding a vacancy among their members, and at any meeting of a Commission two, or such greater number as the Commission may determine, shall be the quorum.
10For the purpose of considering any matter of common concern, the Commissions, or any two or three of them, may hold joint meetings.
11Subject to the provisions of this Act, each of the Commissions shall have power to regulate their own procedure.
12Every document purporting to be an instrument made or issued by a Commission and to be signed by the secretary or any person authorised to act in that behalf, shall be received in evidence and shall, until the contrary is proved, be deemed to be an instrument made or issued by the Commission.