Ask HN: What's the name of this web proposal/standard?

A while ago I came across a web standard/proposal (I think on here) that basically was for reverse linking (e.g. website A writes an article, website B writes an article that is a reply to website A's, website A is able to list all other websites' article replies).

I really can't give any details other than I think it used the Link header and it kind of felt similar to WebSub but it's not WebSub, I'm pretty sure the specific example of article replies was used on the proposal as well; I also think it's likening to "reverse linking" was mentioned, or something about how currently hyperlinks allowed linking in one direction, from source to external source, and this proposal enabled linking in the other direction. Creating a more connected web, something like that.

I think it was a relatively recent standard. Not older than 10 years.

I am also pretty sure it was called "Web" something, but that might be my fault memory conflating with WebSub.

Any ideas?