R.I. Gen. Laws § 44-3-13.4
The town or city councils of any municipality of the state may, by ordinance, exempt from taxation, in whole or in part, the real property situated in that city or town which is occupied by persons or families of low or moderate income. The amount of the exemption and the rules and regulations regarding eligibility for the exemption shall be provided for by ordinance, and the city or town council may, from time to time, by amendment to the ordinance, make those changes in the amount of exemption granted in the rules and regulations regarding eligibility for exemption, as it deems necessary to promote the purposes of this section. The exemption may continue during a term of any mortgage granted by the Rhode Island housing and mortgage finance corporation on the real property, or until the time the real property is not occupied by persons of low or moderate income as their primary residence.
R.I. Gen. Laws § 44-3-13.4