All of the different rights associated with publishing a book can be confusing. Before signing any kind of contract, it's crucial you understand these rights and that you ensure you maintain any rights that could benefit you in the future. Per attorney Greg Victoroff, an author's "subsidiary rights" refer to a derivative work based on or adapted from the original book. This means, if you take the content of your book and use it in a different medium, you are practicing your subsidiary rights. This can include audiobooks, movie adaptations, translations, foreign rights, and more. It's important to check the fine print of any publishing contract to make sure you are not granting these subsidiary rights to your publisher, especially if they don't plan to do anything with these rights.