I'm sure that most of you know that Google is pushing rel=Author as a way to ensure genuine author authority. And I've been looking into this as I have been bringing my blogs into compliance with Google Plus. This has raised some questions, though. Let's say I've got a post that is pretty much an equal collaboration between two people. Can both people get authorship credit? I am actually hoping that the contribution to existing content by a second party will see a rise in popularity in the future.