Established in 1769 Derbrett’s is “the trusted source on British social skills, etiquette and style.” They have just released a 432-page guide that tackles modern dilemmas of etiquette. They have ruled that it is “selfish” to recline your airline seat and deemed it rude to smoke e-cigarettes in the office.

Leaders must not ignore these guidelines however inconvenient. “Politeness,” Theodore Roosevelt said, “[is] a sign of dignity, not subservience.” Emily Post, the famed etiquette scribe, best describes the utility of proper manners:

If you had a commission to give and you entered a man’s office and found him lolling back in a tipped swivel chair, his feet above his head, the ubiquitous cigar in his mouth and his drowsy attention fixed on the sporting page of the newspaper, you would be impressed not so much by his lack of good manners as by his bad business policy, because of the incompetence that his attitude suggests. It is scarcely necessary to ask: Would you give an important commission to him who has no apparent intention of doing anything but “take his ease”; or to him who is found occupied at his desk, who gets up with alacrity upon your entrance, and is seemingly “on his toes” mentally as well as actually? Or, would you go in preference to a man whose manners resemble those of a bear at the Zoo, if you could go to another whose business ability is supplemented by personal charm? And this again is merely an illustration of bad manners and good.

George Washington would agree with Post’s sentiment. As a young man he even wrote a handy list of rules not to be forgotten. Number 11 is a personal favorite: “Shift not yourself in the Sight of others nor Gnaw your nails.”

Leaders must not scoff at Derbrett’s new guide, but rather study its advice with care.