2018-09-25 UTC
# 
@aaronpk ↩️ That’s tricky. hCard (Microformats 1) was/is indexed by Google. The Webmention spec (published in 2017) was published after years of implementations working in the wild. Before Webmention existed, h-card/h-entry was used with Pingback to send comments back and forth. (twitter.com/_/status/1044436721763381249)