- From: Maciej Stachowiak <mjs@apple.com>
- Date: Mon, 28 Sep 2009 14:56:55 -0700
- To: Philip Taylor <pjt47@cam.ac.uk>
- Cc: Henri Sivonen <hsivonen@iki.fi>, Manu Sporny <msporny@digitalbazaar.com>, HTMLWG WG <public-html@w3.org>
On Sep 28, 2009, at 7:27 AM, Philip Taylor wrote: > Henri Sivonen wrote: >> On Sep 28, 2009, at 16:33, Manu Sporny wrote: >>> * RDFa uses @version, which is obsoleted in HTML5. RDFa is also >>> becoming >>> a FPWD, so we have to resolve how we're doing @version and @profile. >>> Either the signaling mechanism has to change for RDFa, or we >>> have to figure out some cross-language extended processing behavior >>> notification mechanism. >> What does RDFa use @version for? What happens in XHTML if there is >> no @version? > > All the current RDFa-in-text/html processors I've tested have > apparently completely ignored the absence of @version. I haven't > noticed any RDFa-in-XHTML processors that care about it either, but > I've never tried testing them in much detail. Sounds to me like @version should be dropped as a mandatory document conformance requirement, at least for HTML+RDFa, and probably for the next version of XHTML+RDFa. - Maciej > > > Looking at some of the examples of RDFa deployment Mark gave > recently in some other thread: > > http://www.civilservice.gov.uk/jobs/careers-detail.aspx?JobId=7808 > http://www.bbc.co.uk/music/reviews/xgjw > http://www.google.com/support/webmasters/bin/answer.py?answer=146898 > > ...none seem to use (or suggest using) @version, nor do they use > @profile for RDFa. > > > Looking at ~425K pages from dotnetdotcom.org, I see 30 pages with > <html version="XHTML+RDFa 1.0">, on 3 distinct sites. > > (The next most common value is 29 pages with version="-//W3C//DTD > XHTML 1.1//EN", on about 14 distinct sites.) > > Examining one page from each of those 3 sites: > > http://taringa.net/posts/musica/3519676/Freddy-Fender---The-Hits-Eamp;-More-Cd-Box.html > tries to use foaf and dc but it doesn't declare xmlns:foaf or > xmlns:dc so a conforming RDFa processor will never extract any data > anyway. > > http://upcoming.yahoo.com/event/419026/ seems to do things properly > (except for an undeclared prefix rel="cal:website" which is > presumably a typo of vcal). > > http://www.calames.abes.fr/pub/ms/D01041301 seems to do things > properly. > > So at least they are all actually using (or trying to use) RDFa. > > Meanwhile, about 180 pages on about 90 distinct sites use > rel="dc:*", indicating the use (or attempted use) of RDFa. > > So less than 2% of pages that apparently use RDFa use @version. > > This has not yet triggered the end of the world, so presumably RDFa > in practice works fine without @version. > > -- > Philip Taylor > pjt47@cam.ac.uk >
Received on Monday, 28 September 2009 21:57:38 UTC