"Other documents" for EEA - RRR

[MisterJ]

Hi all,

I'm filing for Retained Residence as my spouse has left right after we hit 5 years. I would be eligible for PR, but we're separated by borders now, but RRR still makes sense.

The snag is that she won't submit her EU card, and she's lost her passport. It mentions that "other ID docs" can be submitted in lieu alongside an explanation... does anyone know what these docs are? Or if it's a decent idea even to try submitting them? Otherwise I'm going to have to convince her to apply for a new passport and take the time to wait for it...

Thanks in advance