The U.S. dollar in terms of lawful money is defined per the Coinage Act of 1792. All currency is a unit of measure. Relatedly, a "charge" is an "amount" or a "quantity". As for cyclic redundancies, circular arguments or confusion caused by Congress or by Banksters or by whoever--I'm unaware of making apologies for that. One old treatise suggested that despite the term dollar, pound, peso--any payment in money is effectively 'universal' (i.e. exchange rates).
It might be worth noting the difference in laws in the territories of the United States and in the organic states which formed the United States. Each Federal Reserve District is likely construed to be a territory of the United States. Also, as I have indicated in private discussions, the British pounds sterling a standard currency in the colonies and possibly before the Coinage Act of 1792.