This is one of the first signs
Fiat money vs commodity money
Fiat currency, also known as fiat money, is the opposite of commodity money. The difference between fiat money and commodity money relates to their intrinsic value. Historically, commodity money has an intrinsic value that is derived from the materials it is made of, such as gold and silver coins. Fiat money by contrast, has no intrinsic value – it is essentially a promise from a government or central bank that the currency is capable of being exchanged for its value in goods.
"Examples of a fiat currency
Well-known examples of fiat currencies include the pound sterling, the euro and the US dollar. In fact, very few world currencies are true commodity currencies and most are, in one way or another, a form of fiat money."
"A commodity currency is a currency that co-moves with the world prices of primary commodity products, due to these countries' heavy dependency on the export of certain raw materials for income.[1] Commodity currencies are most prevalent in developing countries (eg. Burundi, Tanzania, Papua New Guinea). In the foreign exchange market, commodity currencies generally refer to the New Zealand dollar, Norwegian krone, South African rand, Brazilian real, Russian ruble and the Chilean peso."