Apologies to the Denver Public Library for the previous post today.
A librarian kindly explained the purpose of the stamp placed upon my orphaned book:
The stamp is a quick way to let people know not to return it to the library. Many times public libraries buy several copies of a book when it is new and popular, but after circulation decreases, one or more copies might be removed to allow for more rooms on the shelves since most libraries don't have unlimited space.
More importantly, a search of Denver’s catalog reveals that that they still have 3 copies of UNEXPECTEDLY, MILO, 1 copy of SOMETHING MISSING and a whopping 32 copies of MEMOIRS OF AN IMAGINARY FRIEND (only 8 available).
I don’t know how I ever doubted them.