When you rent books from CampusBookRentals.com, the expectation is that the books will be returned in good condition. Generally, it is advised not to highlight or write in the rented books, as this can lead to additional fees or charges when returning the materials. CampusBookRentals.com encourages customers to handle the books with care to ensure they remain in a reusable state for future students. If any marking or highlighting is done, it may be considered damage. For the most accurate and specific information regarding the renting guidelines, it is a good idea to refer to the terms and conditions found on their website. Additionally, the information regarding how to treat rented books can typically be found in their rental policies section. Always a good practice to be informed before making any decisions regarding the condition of a rented item.