25 CFR § 23.107 - How should a State court determine if there is reason to know the child is an Indian child?
(a) State courts must ask each participant in an emergency or voluntary or involuntary child-custody proceeding whether the participant knows or has reason to know that the child is an Indian child. The inquiry is made at the commencement of the proceeding and all responses should be on the record. State courts must instruct the parties to inform the court if they subsequently receive information that provides reason to know the child is an Indian child.
(b) If there is reason to know the child is an Indian child, but the court does not have sufficient evidence to determine that the child is or is not an “Indian child,” the court must:
(1) Confirm, by way of a report, declaration, or testimony included in the record that the agency or other party used due diligence to identify and work with all of the Tribes of which there is reason to know the child may be a member (or eligible for membership), to verify whether the child is in fact a member (or a biological parent is a member and the child is eligible for membership); and
(2) Treat the child as an Indian child, unless and until it is determined on the record that the child does not meet the definition of an “Indian child” in this part.
(2) Any participant in the proceeding, officer of the court involved in the proceeding, Indian Tribe, Indian organization, or agency informs the court that it has discovered information indicating that the child is an Indian child;
(3) The child who is the subject of the proceeding gives the court reason to know he or she is an Indian child;
(5) The court is informed that the child is or has been a ward of a Tribal court; or
(d) In seeking verification of the child's status in a voluntary proceeding where a consenting parent evidences, by written request or statement in the record, a desire for anonymity, the court must keep relevant documents pertaining to the inquiry required under this section confidential and under seal. A request for anonymity does not relieve the court, agency, or other party from any duty of compliance with ICWA, including the obligation to verify whether the child is an “Indian child.” A Tribe receiving information related to this inquiry must keep documents and information confidential.