A bit more to the story: As mentioned the locations differ because they were hand punched into the dies.
There were punched into a harden die, thus the many times I mentioned mintmark punch damage. This was done from the beginning as new/different mints were used, with no mintmark for the Philly mint as it was the first one. (at that time there was not need for a mintmark as there was just one location) In 1989, the last of the mintmark punching ended. Since then, the mintmarks are created on the dies from mint locations. Thus no more RPMs. The if the mintmark was doubled, then the rest of the die would also be doubled the same:
When we something affecting the post 1990 coins, and it is the mintmark area only affected, it is die wear. On the Single squeezed dies, the affected areas with DDD
will also show a shadow area on the fields of Die Deterioration
always in the direction of the closest rim direction. So after a 1990, there are no more RPMs. (RPM means, Re-Punched Mintmark) With no more punching of the mintmark, there can't be RPMs. CoopHome
: Why are the mintmarks different on some years and not so on other years? Since 1990, Why can't there be RPMs?