Form 23D: cost auditor must notify Central Government of appointment details, scope, and attachments via eForm. Form 23D requires the cost auditor to notify the Central Government via the MCA21 eForm of appointment particulars, scope of cost audit, company identification, and cost audit order details; the eForm must include validated auditor particulars, confirmation of non-disqualification and statutory compliance, attachment of the company intimation, and be digitally signed after successful offline checks and online pre-scrutiny before upload.