Tax Deduction Certificate Forms replaced, introducing form-specific issuance rules and revised annual TDS return deadlines. The circular replaces the unified TDS certificate with Form No.16, 16A and 16B, allocating each form to specific deduction heads and making the new forms effective for certificates issued after 28th February, 1991. It prescribes that Forms 16 and 16A may be printed privately in prescribed proforma, while Form 16B is to be on serially numbered government-printed book forms unless computerised issuers are permitted by the Commissioner. Certificates must be furnished within time-limits under rule 31 and failure to comply attracts penalty under section 272A.