A carrier pigeon stopped to rest on the window sill in the Pentagon building. Close behind him came another pigeon who stopped off to talk. “Where you going?’ asked the second pigeon. “To section M to deliver an order,” answered the first. “What’s the number of the order?” “234XZY-Q78955-421YYTX,” replied the first. “Better get a move on,” said the second. “I got an order to rescind it.”