The regulations in this part apply:
(a) To any tribe which provides in its constitution for petitioning the Secretary or the Commissioner to call elections to amend the tribal constitution;
(b) To any tribe whose constitution or charter provides for petitioning to effect any other action by the Secretary or Commissioner; and
(c) To those tribal members at least 18 years of age who, pursuant to a Federal Statute, may wish to petition the Secretary to issue a charter to their tribe.