If your serious, it's something we do every few years to see how many people live in the US (like how many people live at your house), what race and gender you all are, income and that sort of thing. Basically it just gives the government a general idea of how many people live in the US, whether or not they are citizens and other social and economic shit. You fill them out anonymously and it only effects general population reports and stuff, it doesn't really effect you personally. It's pretty much only used for statistical purposes.

I think the MDHS one is Mississippi child support and this "sovereign citizen" is a deadbeat parent (surprise).