Go to the posted coordinates.
Set A = number of book return slots. Find the cache at:
(A+7)(A-1)(A-2) . (A)(A+6)(A+3) X
Pick a page, 1 page, any page.
Sign it.
You may also write or draw something on the page.
If you’d like, include a picture of that page with your online log. Please, no pictures of the cache or its holder.
Members of a group are each encouraged to sign a page.