I sell the services of website designers and emarketing specialists, business to business, in the UK (among other things). When I do my research I find that quite a few companies' sites return an error without "www." typed before the name.co.uk/com/net. What would you term this? What do web developers do to ensure name.co.uk/com/net without www. open websites without the error message? I'm having difficulty getting this point over to prospective clients and would appreciate your help.