1957 D Penny Errors On Reverse And Overse

Not errors, those are Die Chips or in the case of the B,
a broken post which are considered part of the minting process.
Also a Cud is is break in the rim, not on the fields.

thanks Jimmy and Bacon for your response to my post

These die events are sometimes used as markers. But they happen on both the normal and variety dies. But you can't look for varieties by looking for markers. Because the strike process is the same over and over, the same die events happen on all the dies. Markers only count on varieties if the variety is there. They denote die states. Fresher dies will not have some of the die events, and later die states may have new markers not known before. Sometimes even one die can be changed and the markers will also be different for this die state. Thus they could be part of a new die marriage. Most of the times they try to match the replacement to a similar die state. If no others are available, a fresh die maybe add to a die marriage. So look for the variety first, then see if there is a listed die state so you can compare images with. On Variety Vista, they list more areas where die markers, or die events could happen. So when using this site, to look for the description to see what areas are the actual variety. Why? Because the ones that are not of the variety in the description, will be normal devices as the varieties may not affect all devices. But the fingerprints of the die, may be handy to use to match up to a certain die. Also die markers like die scratches can flatten first in the open fields. So looking at the die events near devices, you might find a matching for a previous die event. Inside of closed devices is where the markers last the longest. Just a few ways you can use die events to ID a variety.

CoopHome: What is the purpose of die events listed with variety coins? What is the wrong way to use them?