At least one field must be set for Hcard.
    Missing required field "name (fn)".

  Missing required hCard "author".

 <span class='post-author vcard'>
          <b:if cond='data:top.showAuthor'>
            <data:top.authorLabel/>
                 <b:if cond='data:post.authorProfileUrl'>
                 <span class='fn'>
                 <a expr:href='data:post.authorProfileUrl' rel='author' title='author profile'>
                 <data:post.author/>
                 </a>
                 </span>
                 <b:else/>
                 <span class='fn'><data:post.author/></span>
                 </b:if>
         </b:if>
    </span>