Indian groups that might be affected by an acknowledgment determination. (12) Letter of intent The term letter of intent means an undocumented letter or resolution by which an Indian group requests Federal acknowledgment as an Indian tribe and expresses its intent to submit a documented petition. (13) Petitioner The term petitioner means any entity that has submitted a letter of intent to the Secretary requesting acknowledgment that it is an Indian tribe. (14) Political influence or authority The term political influence or authority means a tribal council, leadership, internal process or other mechanism which the group has used as a means of influencing or controlling the behavior of its members in significant respects, and/or making decisions for the group which substantially affect its members, and/or representing the group in dealing with outsiders in matters of consequence. This process is to be understood in the context of the history, culture and social organization of the group. (15) Previous Federal acknowledgment The term previous Federal acknowledgment means action by the Federal Government clearly premised on identification of a tribal political entity and indicating clearly the recognition of a relationship between that entity and the United States. (16) Secretary The term Secretary means the Secretary of the Interior or that officer’s authorized representative. (17) Sustained contact The term sustained contact means the period of earliest sustained non-Indian settlement and/or governmental presence in the local area in which the historical tribe or tribes from which the petitioner descends was located historically. 4. Groups eligible to submit petitions (a) Eligible groups Indian groups indigenous to the continental United States that are not federally recognized Indian tribes on the date of the enactment of this Act may submit a petition under this Act. (b) Ineligible groups The following may not submit a petition under this Act: (1) Splinter groups, political factions, communities or groups of