(1) Every notice, order or requisition issued by a Board under this Act or any rule or bye law made thereunder shall be signed--
         (a) either by the President of the Board or by the Chief Executive Officer; or
         (b) by the members of any committee especially authorised by the Board in this behalf.
     (2) Whenever under this Act or any rule or bye-law made thereunder the doing of, or the omission to do, anything or the validity of anything depends upon the approval, sanction, consent, concurrence, declaration, opinion or satisfaction of the Board, a written document signed by any officer or member specified in sub-section (1) purporting to convey or set-forth such approval, sanction, consent, concurrence, declaration, opinion or satisfaction shall be sufficient evidence thereof.
     (3) Every license, written permission, notice, bill summons or other document which is required by this Act or any rule or bye-law made thereunder to bear the signature of the President, Vice-President or the Chief Executive Officer, or of any such member of any committee as has been specially authorised by the Board in this behalf shall be deemed to be properly signed if it bears facsimile of the signature of any such officer or member, as the case may be, stamped thereon.