Registered user

[IOCorp]

I hope I explain well...
It would be of great help if a user whose nick is registered enters the server, he cannot write in any room or private room until he identifies himself.
since on my server, they use registered nicks of other users and bother posing as other people and leave before the services change their nick.
Hopefully something can be done.
Thank you very much.

[CrazyCat]

Use a security-group

[IOCorp]

Use a security-group

Could you tell me how please?.