Non-tax filing parents
Non-tax filing oneself
parents have a business or a farm
The forms section in the IDOC has a combined non-tax filer form while the main page shows that my parents and I need to fill different non-tax filer forms.
You need to contact the financial aid office at the place where you are applying, and ask what they require from students from your country. the Non-tax paperwork is for US applicants who for one reason or another are not required to file US tax returns.