Yes, at the Self-Governance Tribe's option, additional terms may be included as set forth in sections 506 [25 U.S.C. 458aaa-5 ] and 516(b) of the Act [25 U.S.C. 458aaa-15(b) ]. In addition, any other terms to which the Self-Governance Tribe and the Secretary agree may be included.
42 C.F.R. §137.46