Quote:
"whoever adds to the book will be added to the lake of sulfur" type thing.
You do realize that 'the books' didn't exist in the form sold in your local bookstore until a few hundred years after Christ's time, right? Depending on which 'don't add' reference you're using, it can be taken, in Revelation, to be a stricture against THE Book of Revelation. The author couldn't have meant The Books, as found in every motel room, as that book wasn't there to refer to.

The other such rule i can think of is Old Testament. Depends on how you look at it, i think it says that you can add divinely inspired scripture to the litany, but nothing else.
Or, you can't add new stuff at all, which would make the entire New Testament bogus.