Understanding h-cards

I tend to fixate on little details and can't move on till I find the answer. The latest cause was trying to understand the meaning of the h-prefix in h-cards and other class names in microformats.

The documentation has this to say about prefixing conventions:

  • h-* for root class names (e.g. h-card)
  • p-* for plain text properties (e.g. p-name)
  • u-* for URL properties (e.g. u-photo)
  • dt-* for date/time properties (e.g. dt-bday)
  • e-* for embedded markup properties (e.g. e-note)

All of the prefixes made sense to me except for h-. Why h- for root and not r-? I'm sure it's in there somewhere, but I couldn't find an explanation in the documention on the microformats website. So, naturally, I turned to that old reliable source of genuine and generally well-edited material: a book.

A lot has changed between microformats and microformats2, one of the big ones being the introduction of the above prefixes, and if I couldn't figure out where the h- came from, I might find it in the original book on the subject by one of the founders of the spec: Brian Suda. And, sure enough, he explains it very clearly:

We took the vCard spec (RFC2426) and mapped it 1 to 1 to properties that could be placed into the HTML class attribute. Since this was in HTML, it made sense to call this new format hCard, "h" for HTML.

β€” Brian Suda, Using Microformats, p. 19 (O'Reilly, 2006)

So hCard was the original name, and namely an HTML analogue for (and a direct adaptation of) vCard. H stands for HTML.

And in the microformats2 spec, the prefixes are meant to wrangle and make sense of so much that was difficult to remember and parse.

So h- represents the HTML element that serves as the root of the named data type: h-card is the root element for a card containing contact information, h-entry is the root element for an entry in a blog or the like, und so weiter.

An h-card is essentially a block of HTML containing a business card.

There's a lot more to dive into, but that clears up one of those little things that tends to block me from making progress.