((a)) The Secretary has authority to prescribe all rules and regulations which are necessary or appropriate to carry out the laws administered by the Department and are consistent with those laws, including—
((1)) regulations with respect to the nature and extent of proof and evidence and the method of taking and furnishing them in order to establish the right to benefits under such laws;
((2)) the forms of application by claimants under such laws;
((3)) the methods of making investigations and medical examinations; and
((4)) the manner and form of adjudications and awards.
((b)) Any rule, regulation, guideline, or other published interpretation or order (and any amendment thereto) issued pursuant to the authority granted by this section or any other provision of this title shall contain citations to the particular section or sections of statutory law or other legal authority upon which such issuance is based. The citation to the authority shall appear immediately following each substantive provision of the issuance.
((c)) In applying to the Department, the Secretary shall ensure that subparagraphs (C), (D), and (E) of that section are complied with, particularly with respect to opinions and interpretations of the General Counsel.
((d)) The provisions of shall apply, without regard to subsection (a)(2) of that section, to matters relating to loans, grants, or benefits under a law administered by the Secretary.