The screenshot library is a collection of screenshots (or icons) that can automatically be assigned to the item you want to sell. If you don't provide a screenshot yourself, this library will be searched for a match. If a match is found, you can choose to add it to your auction.
The library contains:When you're selling multiple tomes, make sure you name the auction like this: "7 Ranger Tomes". If you name it "7x Ranger Tome" or "Ranger Tome x 7" the icons will not be matched.