While sorting through my immense cast list for a dying storybook, I had the sudden urge to be able to mark characters whose drivers had quit as NPCs on the cast list. It was super simple to figure out, and thus I made @NPC, which is an inactive account because of an email SNAFU of mine.
Basically, when people drop your storybook for whatever reason and you really want their character to stay on, just edit the owner's name to NPC, and it'll show up like this:
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