This is quite easily done with a filter plugin. Here's an example similar to what I use on my site:
function filter_handle( &$handle, $olduser )
// allow admins to have whatever name they like
if ( qa_get_logged_in_level() > QA_USER_LEVEL_ADMIN )
if ( preg_match('/admin|sitename/i', $handle) )
return 'Sorry, that username is not allowed.';
That matches anything with "admin" or "sitename" anywhere in the handle.
Hope that helps!
Welcome to the Q&A site for Question2Answer.
If you have a question about Q2A, please ask in English.
To report a bug, please create a new issue on Github or ask a question here with the bug tag.
If you just want to try Q2A, please use the demo site.
July 15, 2020: Q2A 1.8.5 released!