Hey Ev, what about mentions?
Joe Polastre

I keep coming back to this post and thinking, “Why doesn’t Medium support mentions internet-wide instead of just within their own ecosystem?” Medium could support the W3C’s Webmention spec and essentially support @mentions not only here but even to other sites — including Twitter perhaps? How cool would it be to post a short reply (or like/favorite) on Twitter and have it show up on the related Medium post as a comment/like?!

The concept is essentially a more modern/secure version of trackback/pingback, but with more flexibility.