Fiction subject tagging in libraries is largely ineffectual for a variety of reasons—e.g. a lack of robust, open-access vocabularies, the difficulty of assessing the contents of unread fiction, and unsuitable software. In partnership with the Fiction Filters: Crowdsourcing Website group—who created the host website—we created a core vocabulary of tags in subject areas such as character traits and tropes, which users can add to and use to tag previously read books. This gives power to readers to highlight what they find most important and appealing about books, browse by personal interests, and filter out unwanted content.