State or local authority by registered mail or in person, provided that the court may stay proceedings in such civil action pending the termination of State or local enforcement proceedings. (f) Greater protection under State law This section shall not preempt any law of a State, the District of Columbia, a Tribal government, or a territory of the United States if the protections that such law affords to consumers are greater than the protections provided under this section. (g) Rulemaking The Secretary of the Treasury shall issue such rules as the Secretary determines are necessary to implement this section, which may include prescribing additional exceptions to the application of the requirements described in subsection (a). . (b) Clerical amendment The table of contents for chapter 51 of title 31, United States Code, is amended by inserting after the item relating to section 5103 the following: 5104. Retail businesses prohibited from refusing cash payments. .