If I (as Relph$ sovereign) need to spend more Relph$, I just write on more pieces of paper, I don't need to get them back from the kids first.
#MMT
Likewise as a Relph$ sovereign, I can tax the kids so many Relph$ with penalties for default to ensure that they comply with the system.
Those Relph$ I get from tax just go in a secure bin, I don't need them to spend/create new ones. I can spend as many as I like.
If I want a more modern system I don't even have to write on bits of paper, I could just put entries in a spreadsheet.
Then when I tax my Relph$ I just deduct numbers from the spreadsheet, exactly like happens with the A$ or the US$ or £Sterling etc.