The Google guideline Author information in search results tells us that we need to use the following format to link to the article author:
<a href="[profile_url]?rel=author">Author</a>
However, HTML5 specification has another construction for that:
<a href="http://author's-domain.com" rel="author">Author</a>
So what option should we use on an HTML5 website? Maybe, something like that
<a href="[profile_url]?rel=author" rel="author">Author</a>
, which is proper in both specifications?