Standardisation of industry classification enforces uniform four level coding and mandated issuer reporting for listed debt securities. Issuers must adopt a harmonised four level industry classification and submit prescribed data at ISIN allotment and, post listing, update specified fields to any exchange where listed within 30 days of financial year end and on event basis; the circular deletes the issuer type clause and replaces the sector classification table in the Annex, with applicability to debt issuances opening on or after April 1, 2022.