Hello Numistas,
I'm not sure if this was already discussed, so bear with me please.
What is the difference between a COIN issued by - for instance - a German city, with quite a limited period/geographics of use and, let's say, an as EXONUMIA categorized Belgium or Canadian city token with similar limitations?
Both were accepted and used as local legal tender in the issuing city for certain (short) period of time.
Therefore, pieces issued by any ruling authority and not only by states, meant to be used as money, should be categorized as COINS.