I like how you can reference an issue/commit/PR on Github and then it shows you a link back to the reference. Would be cool if there was a plugin that could make quotes implement some kind of reference system. I guess it would need some new BBC/autolinking functionality. Then a table for message to message link. At the bottom of the page (or somewhere on the messages themselves) it would show references. Maybe in the discussed "notifications" tab, it would show you when someone references your message.