[ZendTo] usernameRegexp question and possible bug

[Der PCFreak]

Hi all,

in preferences.php there is

'usernameRegexp'    => '/^([a-zA-Z0-9][a-zA-Z0-9\_\.\-\@\\\]*)$/i',

It looks to me, that there is a missing "]"

\@ = the character @
\\ = the \ character
\] = ] as a character

So I think we miss the closing "]". I think, this would be right:

'usernameRegexp'    => '/^([a-zA-Z0-9][a-zA-Z0-9\_\.\-\@\\\]]*)$/i',
                                                             ^

Is there something wrong?

And the question I have is, how can I block a specific username from 
logging on the system. Do I have to add him to the
usernameRegexp somehow or is there another way?
Has someone an idea for that. Let's say, I want to block the username 
'paul'?

Kind regards

Peter