(a) Once an official filing has been made, the local Bureau official shall immediately have copies made of the petition and its signatures. The local Bureau official shall keep these copies at the Agency or field office for 15 days following the date of official filing, during which time they shall be available for examination by authorized voters of the tribe upon request. During this 15-day period, challenges of signatures may be filed with the local Bureau official.
(b) Challenges will be considered on the following grounds:
(1) Forgery of signatures; and
(2) Lack of proper qualifications of a signer. No challenge will be considered which is not accompanied by supporting evidence in writing. In the event that an individual's name appears on a petition more than once, all but one of the names shall be stricken.