It seems that things keep getting added to my "Keep One" list in the item manager. I don't add them myself. How are these items being added to that list ? Is there any way to prevent it ?
I don't know, but I'll venture to guess --
Items automatically get flagged as "junk" if you autosell all of them, so maybe they get flagged as "keep one" if you ever autosell all but one of them?
The help button in the item manager was less helpful than it could be.
At this point, I am thinking that it happens when pulverizing but I haven't confirmed that theory.