Italy's Parallel Fiscal Currency: All You Need To Know.
"The basic principles of the fiscal money are two:
First: it is a particular government bond that has a value given to it by the state, even if it does not enjoy the status of a legal tender. In other words, the state binds itself to accept it, e.g. for the payment of taxes or governmental services, while business and citizens are free to use it or not. .
Second: as the bond is not designed to be reimbursed with the euro, which the state can no longer emit, the state is always able to honour its agreement. The bond cannot be exchanged for euros, but bondholders can use this special bond to pay their taxes or services provided by the state. It principle looks like a discount coupon that cannot be exchanged for euros but has a value, and oblige the issuer to provide a discount.
Since the state agrees to accept it but not to redeem it, it can’t default on its obligation. Such a bond is equivalent to a sovereign currency."