hCard is a microformat for encoding the contact information for a person, company, organisation or place. XFN is a microformat that uses URLs to represent people and links between those URLs to represent relationships.
If you've got a URL representing a person, how do publish the contact information for that person? An obvious answer is to include an hCard in the page returned at that URL. However, as far as I can tell there's no way presently to mark up the fact that a particular hCard on a page at a particular URL is the hCard of the person the URL represents, which I find to be an irritating disconnect.
Since I was unable to find any prior art for this, I'll make a straw-man proposal. On my main website I've had for some time my basic contact information marked up with hCard. To support discovery of my hCard, I added
id="contactinfo" to the element that holds the
vcard class and then added the following to
<link rel="me" href="#contactinfo">
My intent here is to say that the element with the id "contactinfo", which in this case is an hCard, represents the same person as the page as a whole. This technique could be used for any other person-related microformat too, such as perhaps an hAtom feed of a person's activity stream. (though
rel="alternate" might make more sense in this case.)
This seems like a nice, straightforward way of filling this missing link. If there's an existing practice I missed then please let me know, or else I'd love to hear feedback on this approach.