<link rel="author">
Links the document to whoever wrote it — a page about the person, or an email address.
In the <head>, it points at a page about the document's author; inside an <article>, about that article's author. The specification even accepts a mailto: — the distant kinship with old <address>, which the herbarium pressed.
History explains the oblivion: Google once displayed authorship in results, fed by rel="author" and Google+, and retired it all in 2014. The headlines buried the attribute along with it — but the semantics never belonged to Google, and it remains in the specification for whoever cares to read.
<link rel="author" href="/sobre/">