Hi
Is it possible to disable username completion when adding users to a channel? I want the my users to add users to channels if they know the fullname.
Basically I do not want my users to invite the people they do not know about.
I believe the guest role should prevent users from seeing users not in the current channel.
If not there are permissions to restrict this
Thanks for the reply. The thing is the guest account is disabled. Can you please tell me what permission does that? I tried to limit some permissions but I still have an issue with it 
I replicated the guest user role as another one and tested with a user of the new role, and that does not help me
It is also weird that I disabled all the permissions to adding any user to any channel/discussion in that role but the user stil able to add users regardless. The guest role suffers from the same issue too. I wonder if this is a bug