So on things where you are searching for certain lions or lionesses (like search or trading) you can look for specific features, but I feel that it could be helpful if we also had an option to look at lions who didn't have a certain trait. This could be set-up by having a whole new selection bar for undesirable traits or possibly a checkbox of some sort.
I think this could be very helpful when looking for certain types of lions, such as how I personally try to avoid lions with blue eyes or normal manes. If this feature was put into place I could look at a wide swath of lions that could have traits I want and would also not have traits I don't want.

Let me know any suggestions and improvements!

Good Ideas:
Suggested by River (#6903)- being able to exclude multiple things in one category, like multiple markings