Approval by the Office of the organization of a Federal savings association or the conversion of an insured association to Federal savings association form shall constitute issuance of a charter and shall be final, provided that the association complies with the procedures set out at Sec. 544.2(a) of this chapter. The charter shall conform with the requirements of Sec. 544.1 of this chapter, the permissible provisions of Sec. 544.2, or other provisions specifically approved by the Office.