In version 4.3, Mastodon introduced OpenGraph creator tags to link to an author's Fediverse account from within a post.

I had implemented it on my website a while back. However, because my instance wasn't using a version that supported it, it didn't show up on my instance.

Since upgrading to 4.3.1, I can now see my posts making use of the creator tag feature.

As you can see from the original post, implementing it was relatively trivial. Another win for open protocols and standards.