A for effort on hiding it. Though if I had to, I would say that the SHL stands for Secret and Hidden Locations. I enjoy reading about history and old forts so reading about secret passages wouldn't be out of the norm for me. I mean honestly, who doesn't like a good mystery about a hidden passage. Might find cool things in there like the secret to Tomen's encyclopedic knowledge or a picture of Finn in a Flyers jersey. Anything is possible.