Now that everybody knows that software and hardware can have easter eggs, the time is right to introduce another kind of easter egg:

documentation easter eggs!

I came across this little gem in a posting on /.:

"Slightly offtopic, I know, but I was once reviewing a
document for a serial-port driver or some such. As these
things usually are, it was page after page of mind-numbing
detail about hardware registers, state graphs, interrupt
handlers and the like. About 3/4 of the way in, the author
described yet another hardware register, which had three
or four bit fields of varying length. One of them was
called "EAD - Earn a Dollar".

Being the naive newbie engineer I was back then, I went in
and asked him what that was, and he promptly handed me a
dollar. He said he had put that in just to see if anyone
would read that far."

Do you know any other documentation easter eggs?