Code of Federal Regulations Title 25. Indians § 25.75.11 Proof of relationship

If the applicant's parents or other Eastern Cherokee ancestors through whom the applicant claims enrollment rights are unknown to the Tribal Enrollment Office, the Tribal Enrollment Office may request the applicant to furnish such additional information and evidence as it may deem necessary to determine the applicant's eligibility for enrollment. Failure of the applicant to furnish the information requested may be deemed sufficient cause for rejection.