When I was renting a piano for my daughter recently, I found an obvious spelling mistake in the lease agreement. This provided great amusement for the rental agent — he had been using the same contract for 20 years and I was the first person to point it out. Unfortunately for me, it was a bitter reminder about one of the key problems of documentation — nobody ever reads it

“This machine kills fascists,” read the words on a guitar that American folk singer, Woody Guthrie, used to carry. In…