The post on the die that forms the center of the "6" broke off and allowed coin metal to flow into the void. It is a Mint error that happens all the time on just about every denomination. Chris
The 1960 Philly small date is the one. The 60-D is a penny. Small or large. As a tool to see the difference between 60 small and large dates, then the 60-D is useful. People mistakenly believe the 60-D is valuable because it is a small date, it isn't. Of the 4 types: 60 large, 60 small, 60-D large, 60-D small, only the 60 Philly small date is valuable. In the 1960 the small date is actually physically smaller and the numbers are tighter and more closed than the large. As for the 1970-S and 1982, I don't think they are physically smaller and the phrase small and large date is just defining a variety and not the actual size. Of the 3 dates I mentioned, the 1970-S seems to be the most subtle and difficult to recognize. The 1982 is easy once you are familiar with the 2 different shapes of the #2.
