2019-01-22 UTC
# 
@schnarfed ↩️ the short answer is microformats, which let the recipient interpret the mention as a reply, like, repost, event rsvp, etc, instead of just a generic page. https://aaronparecki.com/2018/06/30/11/your-first-webmention (twitter.com/_/status/1087792228666204162)