Raven helps you manage notes from books and other reading materials. It solves the problem of disorganized notes that are hard to digitize or revisit, preventing you from losing valuable insights. This tool is for avid readers and anyone who wants to better manage their personal knowledge. It allows you to easily capture, organize, and retrieve information, making your notes more useful. Currently, the tool focuses on note-taking and personal knowledge management. Specific limitations regarding content types or advanced features are not detailed in the provided information.