Tribunal held that as per CBDT Circular No. 19/2019, dated 14-8-2019, no communication shall be issued by any income-tax authority relating to assessment, appeals, orders, statutory or otherwise, exemptions, enquiry, investigation, verification of information, penalty, prosecution, rectification, approval etc., to assessee or any other person, on or after 1-10-2019, unless a computer generated DIN has been allotted and is duly quoted in body of such communication. If an assessment order is passed without mentioning DIN, same would be invalid and shall be deemed to have never been passed. Assessing Officer’s order showed that in body of Assessing Officer’s order, no DIN number was mentioned nor there was any reason of not mentioning DIN number, Assessing Officer’s order was invalid and shall be deemed to have never been passed. Subsequent separate communication of DIN would be a superfluous exercise. Followed, CIT v. Brandix Mauritius Holdings Ltd  (2023) 293 Taxman 285/ 456 ITR 34 (Delhi)(HC)  (AY. 2015-16)