Some world governments and mints have curious issuing policies regarding certain "circulating" coins. In America, you have the dollar coins - which "theoretically could circulate", if only your government had the intestinal fortitude to stop the Federal Reserve Bank from issuing $1 notes. But until and unless that happens, American $1 coins are de-facto NCLT.
Here in Australia, the concept of the "circulating commemorative coin" is not as alien as it is in America (where the only truly "circulating commemorative" was the bicentennial quarter). We find lots of commemorative coins in change, most of which were intentionally issued for circulation. Thus, people finding a "strange coin they've never seen before" in change is not an unusual occurrence, so most people wouldn;t necessarily even notice that a commemorativ coin they'd been given was not supposed to be issued for circulation.
Certain commemorative coins are issued only through certain outlets. The recent series of six $2 coins for the Rio games were issued through a major supermarket chain, for example, given away as change to anyone who asked for them (and frequently to people who did not ask for them, too) but because of their distinctive appearance, the vast majority of them have not "circulated" beyond their original use.
Certain other commemorative coins here are only issued by rolls sold for face value by the Mint. Thus, if you (as either a coin collector or a keen advocate of the scouting movement) wanted to see the Scouts or Girl Guides dollar coins in circulation, then you bought a roll or two, and spent them into circulation yourself. Kind of a "crowdsourced" coinage distribution system.
For Australian "coins that were intended as NCLT but ended up in circulation", I can think of a few. The gold $200 coins were sold for a considerable premium above face value when first issued in 1980, but the gold price collapsed shortly afterwards, causing many of the coins to be spent and banked since a bullion dealer would give them less than $200 for them.
And finally, in 1988, a commemorative $5 coin was issued for the opening of our new Parliament House. They were "sold" at face value from one of the larger banks. So many were issued, and the PVC plastic flips they were sold in ruined so many of them from a collector viewpoint, that there has never been much of a collector premium for them and many were and are have been monetized, either spent or banked. They are, however, too physically large to be considered a convenient form of money, so do not usually "circulate".
Here in Australia, the concept of the "circulating commemorative coin" is not as alien as it is in America (where the only truly "circulating commemorative" was the bicentennial quarter). We find lots of commemorative coins in change, most of which were intentionally issued for circulation. Thus, people finding a "strange coin they've never seen before" in change is not an unusual occurrence, so most people wouldn;t necessarily even notice that a commemorativ coin they'd been given was not supposed to be issued for circulation.
Certain commemorative coins are issued only through certain outlets. The recent series of six $2 coins for the Rio games were issued through a major supermarket chain, for example, given away as change to anyone who asked for them (and frequently to people who did not ask for them, too) but because of their distinctive appearance, the vast majority of them have not "circulated" beyond their original use.
Certain other commemorative coins here are only issued by rolls sold for face value by the Mint. Thus, if you (as either a coin collector or a keen advocate of the scouting movement) wanted to see the Scouts or Girl Guides dollar coins in circulation, then you bought a roll or two, and spent them into circulation yourself. Kind of a "crowdsourced" coinage distribution system.
For Australian "coins that were intended as NCLT but ended up in circulation", I can think of a few. The gold $200 coins were sold for a considerable premium above face value when first issued in 1980, but the gold price collapsed shortly afterwards, causing many of the coins to be spent and banked since a bullion dealer would give them less than $200 for them.
And finally, in 1988, a commemorative $5 coin was issued for the opening of our new Parliament House. They were "sold" at face value from one of the larger banks. So many were issued, and the PVC plastic flips they were sold in ruined so many of them from a collector viewpoint, that there has never been much of a collector premium for them and many were and are have been monetized, either spent or banked. They are, however, too physically large to be considered a convenient form of money, so do not usually "circulate".
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis





















