11. The seal of the Board shall be authenticated by the signature of the chairman of the Board or some other member of the Board authorised by the Board to act in that behalf and of the secretary or some other person authorised by the Board so to act.
12. Every document purporting to be a document duly executed or issued either under the seal of the Board authenticated in the manner provided by this Schedule or on behalf of the Board, or purporting to be signed by the secretary or any other person, being a member, officer or servant of the Board authorised to act in that behalf, shall, until the contrary be proved, be deemed to be a document so executed or issued or so signed as the case may be.