(a) Where the work under a contract is to be performed on an Indian reservation, the CO may supplement the clause at 1452.226-71, Indian Preference Program—Department of the Interior, by adding specific Indian preference requirements of the Tribe on whose reservation the work is to be performed. The supplemental requirements shall be jointly developed for the contract by the CO and the Tribe. Supplemental preference requirements must represent a further implementation of the requirements of Section 7(b) of Public Law 93-638 and must be approved by the SOL for legal sufficiency before being added to a solicitation and resultant contract. Any supplemental preference requirements to be added to the clause at 1452.226-71 shall be included in the solicitation and clearly identified in order to ensure uniform understanding of the additional requirements by all prospective bidders or offerors.

(b) Nothing in this section shall be interpreted to preclude Tribes from independently developing and enforcing their own tribal preference requirements. Such independently developed tribal preference requirements shall not, except as provided in paragraph (a) of this section, become a requirement in contracts covered under this subpart 1426.70 and must not hinder the Government's right to award contracts and to administer their provisions.