Let me be clear, I am not asking about bookkeeping such as maintaining cashflow, expenses, etc.

As a buy & hold investor with a couple rental properties, what forms/paperwork/etc do others hold onto in the form of HARD/PHYSICAL COPIES vs. SOFT/ELECTRONIC copes?  I am thinking of forms like:

-Purchase agreements

-Title Insurance

-Property mgmt agreements

-Closing documents

-Anything & everything else you can think of...

While I'm still early on in my journey and don't have a bunch of properties to catch up on, I want to try to get things in order and sort everything out.  For each property, I want to have a folder or binder with actual hard copies...but I need help distinguishing what is worth keeping and what isn't.

Thanks in advance for any & all advice.