A PNC is essentially a first day cover with a coin included in it. The Australian mints and Australia Post jointly issue these products, and are marketed by both the post shop and the mint shop. It is very often the only way to purchase certain coins and/or stamps. The
RCM and Canada Post don't work together like this, so you don't see official PNC production in Canada (nor in the US), but they're quite popular in Australia and Britain.
PNCs are individually serial numbered (not unlike a banknote). The OP is talking about two identical PNCs (the AFL and AFLW four-coin PNC,
example linked) with the same serial number. Which should be just as impossible as two identical banknotes with the same serial number.
There are two explanations:
- An error in printing the serial numbers caused numbers to appear twice.
- One or both of these PNCs are fake.
To the OP: If we can have one side-by-side picture showing both serial numbers, proving they are indeed the same, that would be great.
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