25 CFR §83.10

1. (a)The Department will consider a criterion in § 83.11 to be met if the available evidence establishes a reasonable likelihood of the validity of the facts relating to that criterion.
   1. (1)The Department will not require conclusive proof of the facts relating to a criterion in order to consider the criterion met.
   2. (2)The Department will require existence of community and political influence or authority be demonstrated on a substantially continuous basis, but this demonstration does not require meeting these criteria at every point in time. Fluctuations in tribal activity during various years will not in themselves be a cause for denial of acknowledgment under these criteria.
   3. (3)The petitioner may use the same evidence to establish more than one criterion.
   4. (4)Evidence or methodology that the Department found sufficient to satisfy any particular criterion in a previous decision will be sufficient to satisfy the criterion for a present petitioner.
2. (b)When evaluating a petition, the Department will:
   1. (1)Allow criteria to be met by any suitable evidence, rather than requiring the specific forms of evidence stated in the criteria;
   2. (2)Take into account historical situations and time periods for which evidence is demonstrably limited or not available;
   3. (3)Take into account the limitations inherent in demonstrating historical existence of community and political influence or authority;
   4. (4)Require a demonstration that the criteria are met on a substantially continuous basis, meaning without substantial interruption; and
   5. (5)Apply these criteria in context with the history, regional differences, culture, and social organization of the petitioner.