Each university may ask for whatever they want. Or not ask anything. In one case, a notarized statement that the federal financial aid will be used for education purpose only. Because the tax documents were sent directly through IRS (FAFSA allows that at the time of filing), so no tax docs were asked. It does sound like a “I shall follow the rules” declaration. But I am not sure of the timeline that university expects to be met. Hopefully they dont hold the admission decision back because of that. Ideally, I dont mind sending such form to the place I shall commit by May 1.