District of Columbia Code Division II. Judiciary and Judicial Procedure § 13-431. Manner and proof of service.

(a) When the law of the District of Columbia authorizes service outside the District of Columbia, the service, when reasonably calculated to give actual notice, may be made --

(b) Proof of service outside the District of Columbia may be made by affidavit of the individual who made the service or in the manner prescribed by the law of the District of Columbia, the order pursuant to which the service is made, or the law of the place in which the service is made for proof of service in an action in any of its courts of general jurisdiction. When service is made by mail, proof of service shall include a receipt signed by the addressee or other evidence of personal delivery to the addressee satisfactory to the court.