<p>Census 2000 definition: “American Indian and Alaska Native. A person having origins in any of the original peoples of North and South America (including Central America) and who maintain tribal affiliation or community attachment.” (I believe “attachment” can be broadly interpreted; I know of no official specific criteria. The main thing is how the child identifies himself and that he pursues some interest in his heritage.) Princeton WordNet-“Amerindian, Native American (any member of the peoples living in North or South America before the Europeans arrived)” IMO, you are good to answer as you wish. Yes, more schools now ask for enrollment or registration numbers (last time I checked this was more rigorousy reviewed at colleges in the US mid-west.) My 2D are part NA, adopted. They have no registration numbers. They checked white, NA. They could have checked AA, as well. They are socially viewed as white. It helps to make the hs aware of the heritage- in our case, we just spoke with the GC a few years ago.</p>