ESG disclosures via BRSR Core require phased assurance and mandated value chain reporting with specified KPIs and disclosure rules. Introduction of a framework mandating standardized ESG reporting and assurance through the BRSR Core, a focused subset of the Business Responsibility and Sustainability Report comprised of key performance indicators across nine ESG attributes. The Core prescribes KPIs and a base methodology for reporting and reasonable assurance, requires phased applicability to top listed entities by market capitalization, and mandates disclosures for the value chain covering partners comprising seventy five percent of purchases or sales by value, with scope and assumptions disclosed.