[kh99]

Originally Posted by noppid

You both forgot lower case letters and a few other characters. Just saying.

The code where that option is used looks like this:

PHP Code:

if (!preg_match('#' . str_replace('#', '\#', $this->registry->options['usernameregex']) . '#siU', $username))
{
    $this->error('usernametaken', htmlspecialchars_uni($username), $this->registry->session->vars['sessionurl']);
    return false;
} 


The 'i' in the siU at the end means ignore case, so that expression will allow lower case. I did mention that no other characters would be allowed, but I added to that post in case it wasn't clear what I meant.