Hi
I think this can be applicable in situations where there is a transition period such as when both two significantly different types circulate alongside for certain periods of time (before they are demonetised). Secondly when the issuing bank will actively sort through coins and banknote and replace it with a new coin or banknote and Finally when there isn't a formal demonetisation status on older currencies.
- For example the Bank of Mexico is actively withdrawing the pre 2009 Centavo coins and any banknotes from 1992- mid 2000s even though they are legal tender and be spent easily but when they are deposited in the bank it is possible they are segregated from newer types and sent to be destroyed.
- Another example can be places where obsolete coin denominations (Canada Cent and Australian 1 and 2 cent coins, or AUS 1 and 2 Dollar banknotes) and previous series coins are still usable but are actively withdrawn by the issuer.
- Coin replacement programs can come under this such as programs in place in the UK and Canada where they actively remove Precious and higher quality base metal coins from circulation.