Here they say that the possessive for "the mayor of New York" is "the mayor of New York's". It's sounds strange to me, and that's a non-native English speaking site... What do you think of it? Is that way to make a possessive correct?
I've recently seen "What a catostrophe!" as the caption on several online images of disastrously-placed apostrophes on public signs. (Piscean's wasn't in that league!)