If you've ever grappled with the guidance notes for a new TV set or a central heating boiler, you'll know that technical manuals are often rubbish. IKEA flat pack instructions are even worse. So how should clear instructions be written? Microsoft believe that they have clarified their software help pages and established a logical and coherent house style. And they're prepared to share their secrets in the fourth and latest edition of their company guidelines - which we've reviewed here.