This depends upon your e-document vault. If you are utilizing CU*Answers' CU*SPY vault, then you can scan Photo IDs and index them by SSN, FName, LName. You can also scan some supporting documentation for loan forms, specifically Insurance, Verification of Income, Life Death & Disability and Title / UCC documents. Those are indexed by Account number, Form, FName, LName. Scanning of any other documents or any other index scheme is not allowed or supported.
If you have an eDOC Online or InHouse vault you are allowed to configure indexing information as you see fit to meet your needs. If you have a 3rd party vault such as COWWW or MVI etc. then it is up to the vault vendor.