(2) Every notice or other document to be issued, served or given for the purposes of this Act by any income-tax authority, shall be deemed to be authenticated if the name and office of a designated income-tax authority is printed, stamped or otherwise written thereon.

(3) For the purposes of this section, a designated income-tax authority shall mean any income-tax authority authorised by the Board to issue, serve or give such notice or other document after authentication in the manner as provided in sub- section (2).