Recognition of stock exchange: MCX must retain client code change records and permit tax investigation access. The Central Government notifies MCX Stock Exchange Ltd. as a recognised stock exchange under the Explanation to clause (d) of the proviso to sub section (5) of section 43 read with rule 6DDB, making the exchange subject to the Income tax Rules framework. The exchange must maintain separate records of transactions where client codes were changed and provide them for inspection and copies to the Director General of Income tax (Investigation). Recognition may be withdrawn for breach of conditions in rule 6DDA and remains effective until SEBI approval is withdrawn or the notification is rescinded under rule 6DDB.