No relinquishment shall be granted for any child who is the subject
of a "child custody proceeding" as defined in the Indian Child Welfare
Act, 25 U.S.C. § 1903, or has been the subject of such a
proceeding within the previous two (2) years; unless such relinquishment
is for the purpose of enrolling the child in a different federally
recognized Indian tribe for which the child would qualify for benefits
not available to the child through enrollment with NHBP.