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Re: RDF-ISSUE-24 (Deprecate Containers): Should we deprecate RDF containers (Alt, Bag, Seq)? [Cleanup tasks]

From: Dan Brickley <danbri@danbri.org>
Date: Fri, 8 Apr 2011 10:28:18 +0200
Message-ID: <BANLkTi=GQ_mYnbPM23D8tMvMo7kPNE68Mg@mail.gmail.com>
To: RDF Working Group WG <public-rdf-wg@w3.org>
Cc: RDF Working Group Issue Tracker <sysbot+tracker@w3.org>
On 8 April 2011 00:04, RDF Working Group Issue Tracker
<sysbot+tracker@w3.org> wrote:
> RDF-ISSUE-24 (Deprecate Containers): Should we deprecate RDF containers (Alt, Bag, Seq)? [Cleanup tasks]
> http://www.w3.org/2011/rdf-wg/track/issues/24
> Raised by: Sandro Hawke
> On product: Cleanup tasks
> The RDF 1999 and 2004 Recommendations include vocabulary and syntax
> (in RDF/XML) for RDF "containers", Alt, Bag, and Seq.
> Although these features are being used, such as in rss 0.91, some experts
> advise data providers to avoid them.

That's RSS 1.0 - http://web.resource.org/rss/1.0/

Can we avoid what Wikipedia call 'weasel words'?
"... some people say, it is believed, many are of the opinion, most
feel, experts declare, it is often reported, it is widely thought,
research has shown, science says, it was proven ..."

It's worth citing the critique(s) explicitly. "Some experts" in this
community can be found to say more or less anything!

Containers are certainly a nuisance to process (as are lists) in RDF.
Not because of the inherent awfulness of the design, but because
representing ordering in a fact-based system is inherently difficult,
especially when we restrict to binary relations.

To my mind, rdf:Alt is worthless and barely coherent. rdf:Bag is almost as bad.

rdf:Seq does have some merit, and some serious 'in the wild' usage.

In a FOAF context (and informed by various discussions with Tom Baker
of Dublin Core over the years) we chose not to use the word

Instead, we mark certain vocabulary constructs as "archaic forms".
That would be my preference. Old documents that used them still mean
what they mean, and nobody is forced to update them for fear of them
becoming unreadable. But the 'archaic' flag is a nudge towards

If we're seriously thinking to deprecate these constructs - we ought
to contact Adobe ASAP. They have the biggest problem since Adobe XMP
instance data is embedded inside PDF, JPEG etc files, and so not
centrally fixable the way many other deployments (eg. social networks)
might be.



> They have no syntactic support in RDFa or Turtle.  Should the WG align with this advice and say these
> features are only to be used for backward compatibility?  (That is,
> RDF/XML parsers must continue to support the syntax, and libraries
> should allow applications to use the features to interoperate with
> legacy RDF systems.)
> Note that RDF "Containers" (rdf:Alt, rdf:Bag, rdf:Seq) are distinct
> from RDF "Collections" (rdf:List).  This issue is about Containers
> only.
> http://www.w3.org/TR/2004/REC-rdf-primer-20040210/#containers
> http://www.w3.org/2001/sw/wiki/RDF_Core_Work_Items#Data_Model_Issues
Received on Friday, 8 April 2011 08:28:47 UTC

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