R.I. Gen. Laws § 44-26-11

The tax administrator is charged with the administration of this chapter, and all forms necessary and proper for the enforcement of this chapter are prescribed and furnished by the tax administrator. The state tax administrator may prescribe regulations and rulings, not inconsistent with law, to carry into effect the provisions of this chapter and these regulations and rulings, when reasonably designed to carry out the intent and purposes of this chapter, are prima facie evidence of its proper interpretation.