h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

If you've finished eating, put your knife and fork on the plate together in the middle. If you intend eating some more, put them one each side of the plate (but still ON the plate). It's amazing how many people don't know this one.

Includeing the busboy

In the south of France in Particular, you use the same knife and fork for the starters and the main course. When you have finished the course your on, place the fork, prongs up, on the left hand side of the plate and then place the blade of your knife in between the prongs.

Also, in France if you go to a resturant, the cutlery is laid out with the bowl of the spoon and the prong of the fork facing upwards. Yet in a French household this is considered inpolite, the bowl of the spoons and the prongs of the forks should be facing downwards.

And when laying the table generally, the blade of the knife faces the plate. I'm surprised too, how many people don't notice this. It's something you look at three times a day from the moment you can walk, almost.

I learned that if you wished to continue eating, to cross your knife and fork, like a lopsided X. And just for clarification, when you're done, the knife and fork are oriented up-down.

Remember the Diner's Club logo? They had these ads where it would start off with a barred circle saying, "universal symbol for no," and then rotate so the bar was vertical saying, "universal symbol for yes," while the card appeared around the logo. It took me a while before I realized the knife-fork connection to the yes part of that ad.