Ill. Admin. Code tit. 89 § 307.15
"Department" means the Department of Children and Family Services.
"Extended family member" shall be defined by the law or custom of the Indian child's tribe or, in the absence of such law or custom, shall be a person who has reached the age of 18 and who is the Indian child's grandparent, aunt or uncle, brother or sister, brother-in-law or sister-in-law, niece or nephew, first or second cousin, or step-parents.
"Indian" means any person who is a member of an Indian tribe, or who is an Alaska Native and a member of the Regional Corporation as defined in 43 USC 1606.
"Indian child" means any unmarried person who is under age 18 and is a member of an Indian tribe, or is eligible for membership in an Indian tribe and is the biological child of a member of an Indian tribe.
"Indian child's tribe" means the Indian tribe in which an Indian child is a member or eligible for membership as determined by the tribe; or, in the case of an Indian child who is a member of or eligible for membership in more than one tribe, the Indian tribe with which the Indian child has the more significant contacts.
"Indian custodian" means any Indian person who has legal custody of an Indian child under tribal law or custom or under State law or to whom temporary physical care, custody, and control has been transferred by the parent of the child.
"Indian tribe" means any Indian tribe, band, nation or other organized group or community of Indians recognized as eligible for the services provided to Indians by the Secretary of the Interior because of their status as Indians, including any Alaska Native village as defined in 43 USC 1602(c).
"Parent" means any biological parent or parents of an Indian child or any Indian person who has lawfully adopted an Indian child, including adoptions under tribal law or custom. It does not include the unwed father where paternity has not been acknowledged or established.
"Qualified expert witness" means:
a member of the Indian child's tribe who is recognized by the tribal community as knowledgeable in tribal customs as they pertain to family organization and child rearing practices; or
a lay expert witness having substantial experience in the delivery of child and family services to Indians, and extensive knowledge of prevailing social and cultural standards and child rearing practices within the Indian child's tribe; or
a professional person having substantial education and experience in the area of his or her specialty. (See Indian Child Welfare Act Checklists for Juvenile and Family Court Judges, Permancy Planning for Children Department, National Council of Juvenile Justice and Family Court Judges, June 2003, P.O. Box 8970, Reno, Nevada 89507.)
"Secretary" means the Secretary of the United States Department of the Interior.
"Tribal court" means a court of jurisdiction over child custody proceedings that is either a Court of Indian Offenses, a court established and operated under the code or custom of an Indian tribe, or any other administrative body of a tribe that is vested with authority over child custody proceedings.
Ill. Admin. Code tit. 89, § 307.15