There’s no longer any excuse for not knowing where Hudson Square is, at least not when you’re actually in it. The Hudson Square Connection recently festooned the up-and-coming neighborhood just west of Soho with more than 50 brightly colored light-pole banners that proclaim either “WORK,” “PLAY” or “CONNECT.” Those three concepts “are really the essential parts of our mission,” said Ellen Baer, director of the Hudson Square Connection business improvement district. “This is our first salvo,” she said of the new BID’s efforts to help the district cement its own identity. “We hope those banners will be up there for a couple of years.”