shelfclear This command deletes all "system books" from all of the bookshelves that are set to spawn books. System books are the books that spawn from the Shard Library.It does not remove the bookshelves from the bookshelf spawn data file.
shelfstock This command restocks all spawn bookshelves to their MaxBooks setting. It also removes any bookshelves from the data file that no longer exist in the world.
spawnshelfdatawipe This will clear the spawnshelf datafile. After using this command, NO bookshelves will spawn books from the Shard Library until you use the newspawnshelf command to add bookshelves to the data file.