; (2) may be filed in advance of, or at the same time as, a group’s documented petition; and (3) shall be produced, dated and signed by the governing body of an Indian group. 6. Duties of the Assistant Secretary (a) Guidelines The Assistant Secretary shall make available guidelines for the preparation of documented petitions. These guidelines shall— (1) include an explanation of the criteria, a discussion of the types of evidence which may be used to demonstrate particular criteria, and general suggestions and guidelines on how and where to conduct research; (2) include an example of a documented petition format which shall provide guidance, but not preclude the use of any other format; and (3) may be supplemented or updated as necessary. (b) Research and preparation of petition The Assistant Secretary— (1) shall provide petitioners with suggestions and advice regarding preparation of the documented petition