Re: Request to publish HTML+RDFa (draft 3) as FPWD

On Wed, 2009-09-23 at 09:52 +0100, Philip Taylor wrote:
> So I believe these attributes (rel, rev, content, href, src) should
> only be permitted on the elements that HTML5 currently permits them
> on.

Certainly it would be wise to consider the appearance of @href and @src
on elements HTML5 does not currently permit them on to be
non-conforming.

They're allowed anywhere in XHTML+RDFa for essentially two reasons:

  - RDFa was written with XHTML 2.0 compatibility in mind. In
    XHTML 2.0 it was planned that any element could be a link,
    and any could embed external images. Hence the attributes
    were allowed anywhere.

  - RDFa is also written to avoid mentioning specific HTML
    elements as much as possible. This is because it is 
    intended to be usable with non-HTML markup languages, like
    SVG, ODF, DocBook, etc. The XHTML+RDFa processing algorithm
    only defines any special behaviour for <head> and <body>.

However, disallowing @rel, @rev and @content from appearing on arbitrary
elements would break current content which relies on the fact that they
can, and break very useful RDFa authoring patterns.

-- 
Toby A Inkster
<mailto:mail@tobyinkster.co.uk>
<http://tobyinkster.co.uk>

Received on Wednesday, 23 September 2009 11:55:19 UTC