25 C.F.R. § 83.4 : Indians — BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR — TRIBAL GOVERNMENT — PROCEDURES FOR FEDERAL ACKNOWLEDGMENT OF INDIAN TRIBES — GENERAL PROVISIONS — Who cannot be acknowledged under this part?

The Department will not acknowledge:

(a) An association, organization, corporation, or entity of any character formed in recent times unless the entity has only changed form by recently incorporating or otherwise formalizing its existing politically autonomous community;
(b) A splinter group, political faction, community, or entity of any character that separates from the main body of a currently federally recognized Indian tribe, petitioner, or previous petitioner unless the entity can clearly demonstrate it has functioned from 1900 until the present as a politically autonomous community and meets §83.11(f), even though some have regarded them as part of or associated in some manner with a federally recognized Indian tribe;
(c) An entity that is, or an entity whose members are, subject to congressional legislation terminating or forbidding the government-to-government relationship; or
(d) An entity that previously petitioned and was denied Federal acknowledgment under these regulations or under previous regulations in part 83 of this title (including reconstituted, splinter, spin-off, or component groups who were once part of previously denied petitioners).

25 C.F.R. § 83.4

80 FR 37887, 7/1/2015