[whatwg] Micro-data/Microformats/RDFa Interoperability Requirement
ian at hixie.ch
Fri Jun 5 21:39:43 PDT 2009
On Sat, 9 May 2009, Manu Sporny wrote:
> > For rel-license, the HTML5 spec defines the value to apply to the
> > content and not the page as a whole. This is a recent change to match
> > actual practice and I will be posting about this shortly.
> Hmm, yes - after re-reading the definitions, they do differ...
> especially in how the hAudio Microformat uses rel="license". I find the
> HTML5 one to be very problematic. Microformats rel="license" is better,
> and the RDFa use of rel="license" is even better (I can go into the
> reasoning if those on the list are curious).
The definition in HTML5 is just a description of how it's used in
practice. It's not what I'd design if I had a choice. However, there's not
much point defining something that doesn't match the reality of the
> For example, in HTML5, how do you express 20 items on a page, each with
> separate licenses? How do you differentiate a page that has 3 primary
> topics, each with a separate license?
You can't, currently. Can you provide a sample of such a page?
> In short - what's the purpose of rel="license" if a machine can't use it
> to help the person browsing identify important sections of a page?
rel=license as it stands today is useful only (as far as I can tell) for
people searching the Web for pages whose main content (e.g. the photo on a
Flickr page, the text of a blog post on a blog post's permalink, etc) is
licensed under a particular license identified by URI.
> Afterall, it's only machine readable, isn't it? What's the sense in
> having rel="license" if a machine can't be sure of the section of the
> page to which it applies?
Generally speaking, search engines are pretty competent at distinguishing
the page's main content from ancillary content such as style sheets or
> More importantly, if you see this as an issue, why don't you see the
> semantic difference between rel="alternate" in HTML4 and
> rel="alternate" in HTML5 as being an issue? That case is even worse,
> exactly the same string - entirely different semantics.
HTML5's definition, again, matches what actual implementations and author
usage is. HTML5 isn't trying to be compatible with HTML4, it's trying to
be compatible with legacy content.
> > You would have to ask them. I tend not to argue with implementor
> > feedback. If they tell me they won't do something, I don't tell them
> > to do it.
> I would expect the primary editor for a web specification to understand
> the reason that every single one of their implementors refuse to
> implement a technique that they use elsewhere in their products.
I believe I do, but I wouldn't want to put words in their mouth on such
> I'd love to ask eacho of them why it is perceived as difficult and
> discuss possible solutions. A public e-mail would be best so that we can
> discuss on this list, but a private e-mail would be fine as well. So
> please, if your organization has decided to not resolve prefixes in
> attribute values, please send me an e-mail.
> After two weeks, I'll check back in with the mailing list to report on
> the number of responses I received and a summary of the reasoning
> (anonymized, of course) for the benefit of this community.
Did you receive any responses?
Ian Hickson U+1047E )\._.,--....,'``. fL
http://ln.hixie.ch/ U+263A /, _.. \ _\ ;`._ ,.
Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.'
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