280-30-10 R.I. Code R. § 5.4
The Division of Motor Vehicles will make available to each member of the Rhode Island Senate and House of Representatives two sets of special motor vehicle registration plates carrying on the first set of plates as a courtesy the word "Senate" in the case of the Senate, and the word "House" in the case of the House of Representatives, and on a second set of plates in addition to the wording above, the letter "a" denoting auxiliary shall be placed on such plates. Such plates will have special identifying numbers corresponding to the number of the senatorial or representative district from which such member was elected. The member will able to use the plates so long as such member is serving during the term for which he/she has been elected as a member of the General Assembly and no longer. The plates will only be assigned to vehicles registered and/or titled in the name of duly elected members of the senate and of the house of representatives of the general assembly.
280 R.I. Code R. § 280-RICR-30-10-5.4