The notice to be left at a residence in accordance with § 1600.2 shall contain the following information:
The notice shall be left, if possible, in any manner at the premises of the requestor that offers a reasonable assurance that it will remain there until retrieved by the resident, such as by being pushed under the internal door on the premises of the requestor or by being enclosed between the external and internal doors of the premises of the requestor, except that mailboxes, mail slots and other receptacles for the U.S. mail shall not be used.
D.C. Mun. Regs. tit. 1, r. 1-1601