Authentication of notices: signature or prescribed electronic issuance validates documents; printed name and office suffice to authenticate. Notices and documents under the Act must be signed in paper form or communicated electronically as per prescribed procedure; they are deemed authenticated if the name and office of a designated income-tax authority are printed, stamped or otherwise written thereon. A 'designated income-tax authority' is any income-tax authority authorised by the Board to issue, serve or give such notice or document and to authenticate it in that manner.