Can I use my ITIN number for IDOC (Institutional Documentation Service)?

I submitted my CSS Profile just earlier today, and College Board asked me to submit required documents to IDOC as part of my CSS Profile. After I logged in and got to “IDOC Student Portal Family Information”, it asks for my SSN, as well as my parents’. Because I do not have a green card yet (I already applied a while ago and it is still pending to this day), I do not have a SSN. I have instead an ITIN number for tax purposes. Should I use that as a replacement for my SSN, or should I just leave that part blank? Both of my parents have their SSNs.

I’m not sure, but, when my son applied he didn’t have a SSN yet, he left the space in blank.
When he received his SSN, contact the University where he was accepted and updated the information.

Perhaps you must be use your alien number ( resident application number),
Itin number don’t show your legal status, just the opposite.

Thank you for the answer! I might just leave it blank, according to what you disclosed above. I do have an Alien Registration Number; I’m guessing I can call College Board and ask if I can use my ARN instead?

Thanks again for your response, I really do appreciate it : )