Certificate of Degree of Indian Blood

A Certificate of Degree of Indian Blood or Certificate of Degree of Alaska Native Blood (both abbreviated CDIB) is an official U.S. document that certifies an individual possesses a specific fraction of Native American ancestry of a federally recognized Indian tribe, band, nation, pueblo, village, or community. They are issued by the Bureau of Indian Affairs after the applicant supplies a completed genealogy with supporting legal documents such as birth certificates, showing their descent, through one or both birth parents, from an enrolled Indian or an Indian listed in a base roll such as the Dawes Rolls.

Source: Wikipedia — Certificate of Degree of Indian Blood (CC BY-SA 4.0)