"Registered but not accessed" indicates users who are registered as chat members but have not yet accessed the chat room. These users will receive new message notifications.
"Invited but not accessed" indicates users who have been sent an invitation but are not yet registered as chat room members. These users do not receive new message notifications.
Only the room creator and administrator users can edit chat rooms.
In group-only chat rooms, changing the chat room name and adding members cannot be performed.