8 C.F.R. § 320.1
As used in this part, the term:
Adopted means adopted pursuant to a full, final and complete adoption. If a foreign adoption of an orphan was not full and final, was defective, or the unmarried U.S. citizen parent or U.S. citizen parent and spouse jointly did not see and observe the child in person prior to or during the foreign adoption proceedings, the child is not considered to have been fully, finally and completely adopted and must be readopted in the United States. Readoption requirements may be waived if the state of residence of the United States citizen parent(s) recognizes the foreign adoption as full and final under that state's adoption laws.
Adopted child means a person who has been adopted as defined above and who meets the requirements of section 101(b)(1)(E) or (F) of the Act.
Child means a person who meets the requirements of section 101(c)(1) of the Act.
Joint custody, in the case of a child of divorced or legally separated parents, means the award of equal responsibility for and authority over the care, education, religion, medical treatment, and general welfare of a child to both parents by a court of law or other appropriate government entity pursuant to the laws of the state or country of residence.
Legal custody refers to the responsibility for and authority over a child.
(1) For the purpose of the CCA, the Service will presume that a U.S. citizen parent has legal custody of a child, and will recognize that U.S. citizen parent as having lawful authority over the child, absent evidence to the contrary, in the case of: