Ajax Register - restrict username characters

Hello,
I want to add a list of forbidden characters in the username form.
How can I do it ?
Thanks

Hello,

You go to AJAX Register dashboard and click on Options button.
Then under Filters tab there is a fields called "Blocked usernames". Here you can list words to be blocked from registration. It also supports wildcards so you can block characters too. For example, if you want to block "@" you would enter:
*@*

Hello,
Thanks, it works but the message for the user is : This Username is already taken.
It should be great to have an option to inform the user that the character is forbidden.
The top should be an admin parameter to allow only numbers, character upercase, lowercase etc... of course, it's a dream on my side, i don't know the work it needs !
But in all cases, Thanks for your strong Register extension !

Hi,

About the error message, you can edit the language string, either in the language file or with language overrides to say something like:
"This Username is already taken or not allowed.".