FWIW, sovereign citizens don't call themselves that.
One of the best tests is to ask the question directly: Are you a sovereign citizen?
Someone who isn't: no.
Someone who is: You can't be a sovereign citizen, that's an oxymoron followed by a 1,500 explainer containing legal-sounding words.
Or 'sovereign citizen' and 'moron'
@jjmacnab Sometimes they even like to throw in some amusingly nautical language about the "ship of state" and "admiralty courts."
"The court therefore feels some measure of responsibility to inform defendant that all of the fancy-sounding legal things he has read on the Internet are make-believe." β Leaming v US
If you think I'm kidding, do a google search on "sovereign citizen" and "oxymoron."