Nowadays I think most people (me included) would need to have "flong" explained to them - or to google it of course: https://en.wikipedia.org/wiki/Flong (funny that the Wikipedia article contains a reference to the Guardian hoax).
"The San Serriffe hoax is ranked fifth in the top one hundred April Fool's Hoaxes by the Museum of Hoaxes." One should always be skeptical of an entity calling itself that, of course, but I look back rather wistfully to the days when #10 was an amusing hoax.
