A : So I want to discuss about this B : @A great this is a very important subject C : yes me too ... C : @A, @B are you there? A : I'm there I was on another chat. I didn't see you B : yes me too ... B : C are you there? Let's talk about this C : Yes I'm there I didn't see your message because of trafic D : @A @B @C I would like to add something about this A: Indeed we should notify everyone when we talk about this. A : Damn A : @B @C @D Indeed we should notify everyone when we talk about this. B : Right! B : @A @C @D Right! NO MORE! If A wants to talk about this the keyword #this appears somewhere in the spectrum interface along all other active keywords. Each keyword is local to a chat and auto-delete if not used for some time. Any other person sees the keyword on his interface and click on it which highlight every message refering to this and tags any message he tips with #this as long as #this is selected, he will get notification about the message tagged with #this and so does C, D, E, F So now, everybody is notified for some conversations while seeing all the chat, with highlights on things he is interested. Plus, when you enter the chat you can quickly get up to date with topics and see the previous replies. This is not a private chat. The conversation is public and anybody can see it and participate.