Here is a tip: If the "error" cuts into the coin (it goes into the surface rather than being raised), then it’s probably post strike damage. If the coin has a raised blob of metal next to or near a groove or cut, that’s probably post strike damage too.
There are more articles about the coin-making process at the link I've provided (below). I think you should study them. https://www.coinnews.net/2013/09/20/how-the-philadelphia-mint-makes-coins-for-circulation/
I quit Sir but thank you though. My job is stressful. But finding errors is more stressful too lol ☺️Have a good one
Collecting coins should be fun. The only thing I can imagine that would be stressful is if one is expecting to find errors among circulated coins to pay the bills. It ain't gonna happen! ~ Chris