Do we need to retain old H1B petition documents?

[vortexmak]

I have stacks of copies of H1B petition request documents that were sent by lawyers to me for the past 10 years.

Those documents were never asked for in any of previous visa stamping. I have safely retained the i797 approval notice for all previous approvals

Do we need to retain a copy of those petition request documents or can I recycle it?