by the United States government

“ A certificate of acknowledgment is not required for the validity of a transfer, but is prima facie evidence of the execution of the transfer if—
(1) in the case of a transfer executed in the United States, the certificate is issued by a person authorized to administer oaths within the United States; or (2) in the case of a transfer executed in a foreign country, the certificate is issued by a diplomatic or consular officer of the United States, or by a person authorized to administer oaths whose authority is proved by a certificate of such an officer. ”

“ A transfer of copyright ownership, other than by operation of law, is not valid unless an instrument of conveyance, or a note or memorandum of the transfer, is in writing and signed by the owner of the rights conveyed or such owner's duly authorized agent. ”

“ RECORDATION AS CONSTRUCTIVE NOTICE.—Recordation of a document in the Copyright Office gives all persons constructive notice of the facts stated in the recorded document, but only if—
(1) the document, or material attached to it, specifically identifies the work to which it pertains so that, after the document is indexed by the Register of Copyrights, it would be revealed by a reasonable search under the title or registration number of the work; and (2) registration has been made for the work. ”