The computer industry is so overwhelmingly an American industry that people working in it have got to understand the language, so we make no apology for the odd piece of American slang that finds its way into Computergram, but perhaps one or two recent ones need elucidating: a cat-bird is an American thrush that makes a mewing sound, and to be in the cat-bird seat is to be in an enviable position – but if anyone can tell us the derivation, please do; a shoo-in is a dead cert in a fixed horserace where the other jockeys have agreed to shoo the chosen winner to the post; and hanging out a shingle is putting up a nameplate – we assume because people in New England where many of the houses are shingled, rooved and fronted with wooden tiles or shingles, professional and tradespeople used to write their occupation on one of these tiles and hang the thing out by the front gate.