The hyperinflation happened, yes, but the point is that once it stabilised "pre-1991 notes and subsequent forgeries were treated as the same currency." I'm not

The hyperinflation happened, yes, but the point is that once it stabilised "pre-1991 notes and subsequent forgeries were treated as the same currency." I'm not attempting to say this was a good situation, only that it has interesting implications for "what is a currency" as a question.