If that was not a question that you are going to respond to specifically , please give me a sign , so i can at least consider my current user name , further .
Click on your avatar (to go to your profile) and look in the address bar. You'll see that the URL is entirely in lower case, even though your username isn't. i.e. 'BertieWooster' and 'bertiewooster' would have the same profile (unless, of course, the Ed could be persuaded to completely remove all reference to the banned user from AB's records).
Some websites only allow you to use letters and numbers in usernames but I've just logged out and gone to AB's registration page, to see that there seem to be no such restrictions here. Indeed, the user with the greatest number of 'best answers' is someone with a hyphen and a space in their name; that's 'Lie-in King' (which appears as 'lie-in-king' in the URL of his profile page).
That suggests that both 'Bertie-Wooster' and 'Bertie Wooster' would be possible (and that they'd have the same URL for their profile page).
For the avoidance of doubt - i take it you mean Berti.Wooster ( with the dot between the i and w ( your typing says Berti Wooster , i.e with a space - i assume a space is not allowed )
I'm not sure about 'Bertie.Wooster' however. That would mean a dot appearing within the URL of your profile page, which might (depending upon how AB's techies have configured things) be a problem.
it's not quite as clear cut as you think, my previous id was dotty. that's dotty woth a full stop after it. I couldn't sign in as dotty or Dotty, it had to have the full stop, yet, when I checked to see if dotty without the full stop was available, the answer was no, because of dotty., that means that the characters are being ignored by the filter or log in thingy or whatever decides if an id has been used before.