Comment 5 for bug 827970

I'm fine with whatever we do. My main suggestion would be that, for clarity's sake, I think that the values should rise from -1 or 0 at the beginning of a book's journey and end at the final value, be that 4 or 6, with the states inbetween signifying the steps in the process toward becoming a fully derived book. Going from -1 to -2 to 4 feels wrong, as I think it seems confusing to someone who doesn't understand the history of the convention.