"Unlike manners, there isn’t a universally-agreed objective standard" :)

Manners aren't universally agreed either, they are very much tied to the culture people are evolving in. Burping in the middle-east is appropriate and a courtesy to your host, I doubt it'd be very much enjoyed in a White House dinner. Taking some (good?) wine as bottom's up is respectful to your boss/partners in China, yet I believe some of your guests in France would find this offensive ;)

Interesting read nevertheless.