Psychotics are consistently inconsistent. The essence of sanity is to be inconsistently inconsistent.
Information wants to be useful.
I think I'll side with the pissheads on this one.
An initial underscore already conveys strong feelings of magicalness to a C programmer.
It should be illegal to yell 'Y2K' in a crowded economy.
It won't be covered in the book. The source code has to be useful for something, after all.