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Re: Strange HTML5 errors on a Wordpress website

From: Michael[tm] Smith <mike@w3.org>
Date: Mon, 6 Jun 2011 14:38:22 +0900
To: Titti <tittisant@tin.it>
Cc: www-validator@w3.org
Message-ID: <20110606053821.GG331@sideshowbarker>
Titti <tittisant@tin.it>, 2011-06-01 11:11 +0200:

> Hi,
> I notice some odd validating errors on my website. Only until some days
> ago, site was all validated (except for a single warning on a core file
> of the Wordpress calendar).
> Now I find it full of "errors", without having changed anything, but the last updates of WordPress.
> I checked with no plugins and the default theme, but errors are still there.
> They seems to be on Wordpress code, are they?
> That’s very strange, I would like to understand and, if possible, fix them.

I recently updated the backend for the HTML5 facet of the validator, to
bring it into closer conformance with the current HTML5 spec. So the
validator is now doing some checks that it was missing previously. That is,
it's checking conformance constraints that were already existing in the
spec, but which the validator had not yet implemented.

> Some examples:
> 
> Validating http://www.bluesreviews.it/category/bluesandpics (33 errors)
> Error [html5]: ""
> W3C error message: "An img element must have an alt attribute, except under certain conditions"
> - Seems like all thumbnails on that page are missing of the "alt" tag attribute.

Right. Those error messages are all for cases that are actual errors as far
as the spec is concerned. Those thumbnail images should all have alt
attributes with values that provide a textual equivalent of the image. For
example, "View of the steeples of St. Louis Cathedral, from in front, at
the ground level looking up at steep angle."

> That’s singular, ‘cause I haven’t changed nothing, and they already have alt attribute, so no errors before now. 

The images on the pages those thumbnails link to have alt attributes, yeah.
But the thumbnails also need to have alt attributes, in order for any users
who can't see them to have any idea at all what they are.

> Every image on my website have alt attributes.

Those thumbnails are images.

> Validating http://www.bluesreviews.it/ (21 Errors)
> 
> W3C error message: "Bad value archives for attribute rel on element link: Keyword archives is not registered”
> 
> - That’s on every entry of my monthly archives (again, maybe the WP widget calendar, but when I removed it errors was still there)
> 
> W3C error message: "Bad value EditURI for attribute rel on element link: Keyword edituri is not registered”
> 
> - It’s the same for “wlwmanifest”, “index” and “canonical” keywords, but they have always been there.
> 
> W3C error message: "Bad value google-site-verification for attribute name on element meta: Keyword google-site-verification is not registered”
> 
> - My line is: < meta name="google-site-verification" content="GlHj9P4vhSWSq0Odu5QRc8irQHLpHEZSlJ8cNI1y8dg" >, and has always worked well.
> 
> Well, I don’t put all the pages here, these are quite enough.
> Please, can you tell me what’s happening?

The HTML5 validator now checks all rel values to make sure they are either
values that are predefined in the HTML5 spec itself, or defined on the
Microformats Wiki "existing rel values" page.

The error messages themselves provide a link to the relevant part of the
HTML5 where the conformance constraints on rel values are defined, as well
a link to the Microformats "existing rel values" page where new values can
be added. If you have a spec that defines what rel=archives,
rel=wlwmanifest, and rel=google-site-verification mean, you can add those
values there, with a link to the spec, and then next time we update the
HTML5 backend of the validator, those values will no longer be reported as
errors.

  --Mike

-- 
Michael[tm] Smith
http://people.w3.org/mike
Received on Monday, 6 June 2011 05:38:26 GMT

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