In Brazil in the 80's and early 90's, the currency changed name several times. It was called "cruzado", then "cruzeiro", then "cruzado novo" (yep, "new" <old-name>, very creative) and then I think it went back to just "cruzado" :D before finally becoming Real (which I believe was the name of the currency also during Monarchy, 100 years earlier).
This is interesting but it doesn’t really seem like a separate currency. It’s more like Scottish pound vs English pound, it’s the same currency but different banknotes for different regions in the same state.
Quick question for database gurus here. Is it ok to have a currency table using the currency code as primary key?