R.I. Gen. Laws § 31-37-13: Advertising statements to include taxes with price — Inclusion of all prices offered in advertisement.

(a) Any advertisement of motor fuel by a retail dealer which states, refers to, or relates to the price of motor fuel, shall state that the per gallon price includes all taxes imposed with respect to the manufacture or sale of the motor fuel, or shall state the amount of the taxes separately and apart from the selling price or prices.

(b) To provide for truth in advertising, any retail dealer of motor fuel who chooses to advertise the price of any grade or type of motor fuel, in addition to the mandatory requirements of § 31-37-11, shall post in that advertisement (sign or otherwise) all of the prices of each and every grade or type of motor fuel offered by the dealer for sale. The numerals for every price offered for sale shall be equal in size and character.