On cold days people in Manhattan like to take their children to PlaySpace, an indoor playground full of wonderful climbing and sliding contraptions. There's just one irritating detail: when you pay your money, the cashier pulls out a felt-trip marker and an adhesive label tag and asks you your name. 'Frum, I say. 'No, your first name.' 'What do you need my first name for?' To write on the tag, so all the children and the staff will know what to call you. 'In that case, write ' Mr. Frum.'' At which I am shot a look as if I had asked to be called to Duke of Plaza Toro. In encouraging five-year-olds to address grownups by their first names, PlaySpace is only slightly ahead of the times. As a journalist, I faithfully report that the custom of addressing strangers formally is as dead as the practice of leaving a visiting card. There's hardly a secretary left who does not reply, when I give a message fro her boss, 'I'll tell him you called, David.' Or a public relations agent, whether in Bangor or Bangkok, who does not begin his telephonic spiel (长篇大论) with a cheerful 'Hello, David !' You don't have to be a journalist to collect amazing first-name stories. Place a collect call, and the operator first-names you. The teenager behind the counter at a fast food restaurant asks a 70-year-old customer for his first name before taking his order. Habitual first-names claim they are motivated by nothing worse than uncontrollably high-spirited friendliness. I don't believe it. If I asked the fast-food order-takers to lend me ＄ 50, their friendliness would vanish in a whoosh. The PR man drops all his cheerfulness the moment he hears I won't go along with his story idea. No, it's not friendliness that drives first-namers it's aggression. The PR agents who call me David uninvited would never, if they could somehow get him on the phone, address press baron Rupert Murdoch that way. The woman at the bank who called me David would never first-name the bank's chairman. Like the mock-cheery staff at PlaySpace, they are engaged in a smile-faced act of belittlement, an assertion of power disguised as good cheer. 'PR' in paragraph 6 stands for ______.