The CSS Profile is used by private US institutions and a few public ones to determine a student's non-federal financial aid.
The form and completion information can be found here: https://cssprofile.collegeboard.org/
CSS Profile is thrugh College Board. Since it is being sent from an external organization to your designated university, there is a cost to send it. $26 for the first school and $16 for each additional school. Also, plan for it to take up to two weeks for the university to receive the document.