The portmanteau NYLON, also spelled NYLon or, less often, NY-Lon, starts with the concept of New York City and London as twin cities – the financial and cultural capitals of the Anglo-American world – and takes the concept a step further, treating the two cities as "a single city separated by an ocean". There is a community of high-earning professionals who commute with extreme frequency – sometimes several days in a given week – between New York and London on transatlantic flights.