D.C. Code § 42-112: Acknowledgments in Philippine Islands and Puerto Rico.

Deeds and other instruments affecting land situate in the District of Columbia may be acknowledged in the Philippine Islands and Puerto Rico before any notary public appointed therein by proper authority, or any officer therein who has ex officio the powers of a notary public; provided, that the certificate by such notary in the Philippine Islands or in Puerto Rico, as the case may be, shall be accompanied by the certificate of the Executive Secretary of Puerto Rico, or the Governor or Attorney General of the Philippine Islands to the effect that the notary taking said acknowledgment was in fact the officer he purported to be.