Hubzilla Documentation:



Called when creating a new channel or changing the channel name in mod/settings.php

Hook data consists of an array

        'name' => supplied name

    If the hook handler determines the name is valid, do nothing. If there is an issue with the name,
    set $hook_data['message'] to the message text which should be displayed to the member - and the name will
    not be accepted.


        if(mb_strlen($hook_data['name']) < 3)
            $hook_data['message'] = t('Name too short.');