I read recently about, for lack of a better term, a rogue block that was recorded into the blockchain that forked the chain but it didn't split exactly. I read that there is some code in later versions that looks for that bad block, but that there's no telling if that bad block is still out there. Can someone speak more about the code that checks for that? Is there any way to manually check or run that code/command to check, and verify for myself? Any additional info about that block is appreciated!