This subtitle applies to a transfer within the scope of § 13–302 of this subtitle made on or after July 1, 1989, if: The transfer purports to have been made under the Maryland Uniform Gifts to Minors Act; or The instrument by which the transfer purports to have been made uses in substance the designation “As custodian under the Uniform Gifts to Minors Act” or “As custodian under the Uniform Transfers to Minors Act” of any other state, and the application of this subtitle is necessary to validate the transfer.