Envelopes or other materials which are used to enclose official mail shall bear upon its facing, in addition to the name and address of the agency mailing the official mail, the words “official business.”
D.C. Code § 2-703
Marking requirements for envelopes
Apr. 7, 1977, D.C
Official source: D.C. Law Library (Council of the District of Columbia). Reproduced from public-domain District of Columbia statutes; confirm against the official source for the current text. Not legal advice.