As the title says. I'm writing guide and reference books (Amazon short-reads) aimed at people who aren't tech-savvy with the goal of improving their tech literacy. I've seen books like the one linked below which are guides to an existing product that don't seem to come with any sort of official seal of approval. I'm wondering if these are just sitting ducks in a legal grey area, or if these are protected by fair use or some other legal defense.


[Here](https://rads.stackoverflow.com/amzn/click/com/B08LCZS49M) is an example of what I'm talking about.



What are the license/legal requirements to write a guidebook about a specific product?