(a) Orders of the Commissioner shall not be effective unless made in writing and signed by him or by his authority. Every order shall contain a concise statement of the grounds upon which it is based.
(b) Every notice required to be given by the Commissioner to any person shall—
(1) be in writing in detail sufficient reasonably to inform the person of the action taken or proposed; and
(2) designate the provisions of this title pursuant to which action is so taken or proposed; and
(3) state the grounds for such action.
(c) An order or a notice may be given by delivery to the person to be ordered or notified or by mailing it, postage prepaid, addressed to him at his residence or principal place of business as last of record in the Commissioner's office.