Permitted categories of official mail

D.C. Code § 2-702 — under Official Correspondence..

D.C. Code § 2-702

Except as otherwise provided in this chapter, a government employee may not mail, as official mail, any matter, article, material, or document for any reasons other than the following: (1) A request for the matter, article, material, or document has been previously received by the agency; (2) The mailing of the document is required by law; (3) The material or matter requests information pertinent to the conduct of the official business of the agency; (4) The material contains information relating to the activities of the agency or to the availability of agency publications or other documents; (5) The enclosures are forms, blanks, cards, or other documents necessary or beneficial to the administration of the agency; (6) The materials are copies of federal, state or local laws, rules, regulations, orders, instructions, or interpretations thereto; or (7) The materials are being mailed to federal, state, or other public authorities.