Sovereign citizens often get started by the siren song of magic money loopholes, which unfortunately people charge them money for as part of a pretty gnarly scam.
The basic logic of the scam is that when we moved off the gold standard, money stopped being money because it wasn’t backed up by anything “real”.
Since money isn’t actually real money, you can instead give a “coupon” or other named bit of paper that says it’s redeemable for the substance that backs the money, because that’s what money is.
So instead of paying with hard to get paper that’s not backed by gold, you pay with easy to get paper that’s not backed by gold.
The catch, of course, is that’s not what money is, how it works, someone is charging real money for this, and it’s a federal felony.
So this person is, at best, in financial distress leaving them vulnerable to a cruel scam, and ignorant and gullible enough to believe some very odd things about the law involving YOUR NAME IN CAPITAL LETTERS being legally distinct from Your Name In Title Case.