I think you are saying that if one endorses a check, one is signing a contact. If so, how would one find out what the contract is?

And how would one endorse cash in any form, or do you mean use cash in any form?

What is the nature of the private credit -- is it something the user (other than the U.S. Gov't) is required to pay back?

What does FDR saving the Fed from the run in 1933 have to do with accepting private credit?

Where is the contact stating that there is a fee for accepting private credit?

Where is the contact stating that there is a fee for using this private credit to purchase goods and services or for any other use?

I am asking these questions because I don't see that searching through threads is a workable route towards understanding this -- I have watched your video and looked at a number of threads.