7 C.F.R. § 800.45
(c) Proof of authorization. If an application for official services is filed by a person representing the applicant, the agency or the field office receiving the application may require written proof of the authority to file the application.
(Approved by the Office of Management and Budget under control number 0580-0012)
(Secs. 8, 9, 10, 13 and 18, Pub. L. 94-582, 90 Stat. 2870, 2875, 2877, 2880, and 2884, 7 U.S.C. 79, 79a, 79b, 84, 87, and 87e)
[49 FR 30913, Aug. 2, 1984, as amended at 50 FR 45392, Oct. 31, 1985; 54 FR 5924, Feb. 7, 1989]