[BetterRed]

@sbenz - Gotcha - yes I can see how a 'bad-word, count' list for every book could be regarded as 'cluttering' - especially if it's short-lived.

You probably did explain it well enough, but these days my brain disengages when I see 'programmer' lingo.

You can add one of any 'file type' to a book. So for example you can add an MP3 file to a book, calibre itself can't do much with an MP3 except hand it off to the OS in the hope it knows what to do with it. There's also an Open With PI that will hand off a file type to a designated program

So you could write the 'bad-word, count' list for a book in calibre's current temp folder with a name of <some random string or other>.bwlist, and then add that file to the book. You would then have a BWLIST 'format' in the book, calibre will then take care of it - ie not lose it if a folder is moved or renamed - but like an MP3 it won't be able to do much with it. Some alternatives for the internal representation that spring to mind include - json, csv, serialised.

BR