[html5] HTML5 and Microformats

Henri Sivonen hsivonen at iki.fi
Mon Jun 6 05:21:43 PDT 2011

On Sat, 2011-06-04 at 19:27 +0200, Mathias Roth wrote:
> I’ve spent some time this weekend trying to find out why
> http://validator.w3.org does declare most of the “rel” attributes in
> head and body, recommended by XFN, hCard, Dublin Core, ICBM and
> others, as non-valid since some days. Some of them are very
> etablished, some of them are yet unofficial, but used widely.

> Not even the quite useful <link rel="canonical" validates anymore!

The reason why they don't validate is that at the time of the latest
validator code change and deployment, those keywords weren't registered
in the rel keyword extension registry. HTML5 has limited the validity of
rel keywords for a long, long time, but this was implemented in the
validator only recently.

Only the implementation makes people care about the registry, so we
didn't quite get a running start. Furthermore, the W3C HTML WG decided
to move the registry to a different venue, which had the effect of
resetting the registration efforts, since the old registry and the new
one have different licenses, so the old one couldn't be copied and
pasted over wholesale.

XFN and rel=canonical now validate at http://html5.validator.nu/ because
they have been registered. It may take a while until
http://validator.w3.org/ gets redeployed.

> I’ve read about the deprecated “profile” tag, and replaced it by
> “prefetch” in the head (which I guess only works in FF), and added an
> <a rel="profile" href=http://gmpg.org/xfn/11> to the bottom, as
> recommended by Tantik Celik.

"profile" is not relevant here.

> I’ve decided to remove all my “valid html” validator links for now
> (although I really hate to not have it on 100%, and that is still the
> fact), and to keep on using what I have: HTML5 templates and microdata
> – hoping that this is a passing muddle. If there is any other way,
> your advice is very welcome.

You can help by registering stuff by following the links in the error
messages that the validator shows you and editing the wikis with the
information that the HTML(5) spec(s) require registrations to have. The
registry changes aren't reflected in real time. I suggest you give the
W3C validator maintainer a week or so to redeploy after you've made

Henri Sivonen
hsivonen at iki.fi

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