A panda walks into a cafe. He orders a sandwich, eats it, then draws a gun and fires two shots in the air. Why? asks the confused waiter, as the panda makes towards the exit. The panda produces a badly punctuated wildlife manual and tosses it over his shoulder. I'm a panda, he says, at the door. Look it up. The waiter turns to the relevant entry and, sure enough, finds an explanation. Panda. Large black-and-white bear-like mammal, native to China. Eats, shoots and leaves. So punctuation really does matter, even if it is only occasionally a matter of life and death. This is the zero tolerance guide.