I've run into this issue where the town library generates several (sometimes 5-6) copies of the same book, in every bookcase, for every book except skill ones. It takes a lot to scroll through the list and, frankly, having so many copies is utterly useless. Any clue on how to get rid of them? I don't mind 2-3 copies of every book, but this is overkill. This is all taking place at the community library, not at home.

I do have Master Controller, Story Progression etc. if it helps.

IIRC Nraas Overwatch (or other element of the suite) has option for cleaning duplicate books.

I haven't found anything in the Overwatch settings :/
Closest I've found is in Story Progression, under Lots: "Cleanup Duplicate Library Books", which I've set to True. Should I enable "Remove Zero Value Books" as well? I'm afraid the skill books will be removed too...

that was this option (my great memory... It's because I play without memories, so I have not memory, memories... ups, now it seems embarrasing the next post I 'll write in simlish ?).

I'm rather sure than 0-value books does not include any skill book but it definitelly needs confirmation.

OK, I did some testing; I modified some options in SP, then deleted all the books in the library with Master Controller and let the game regenerate them. It appears the issue was with NPCs writing books; there were about 1500 regular books, and a whopping 5000 written by Sims - which, unfortunately, were titled the same as the books programmed by EA. This explains why two copies of "Special Snowflake" had the generic book cover instead of the red one reserved for romance novels.

These are the settings I used for SP (all under General \ Lots):
Automatic Cleaning: set it to anything other than 0
Cleanup Duplicate Library Books: False
Remove Zero Value Books: False
Repopulate Empty Library Shelves: True

And under General \ Skills, I disabled Push Writing. I don't really care about inactives writing books.

Edit: oh, and I also disabled "Add Written Books to Library", under General \ Skills.