Quote regarding the possessive 's'

I love this quote from the Chicago Manual of Style which is apparently the guide to punctuation and grammar followed by most book publishers.

How to form the possessive of polysyllabic personal names ending with the sound of "s" or "z" probably occasions more dissension among writers and editors than any other orthographic matter open to disagreement.

I happen to be rereading The Hitch-hiker's Guide to the Galaxy and this quote sounds like something I just read in that book. Funny.