W3C home > Mailing lists > Public > w3c-rdfcore-wg@w3.org > May 2001

Issue http://www.w3.org/2000/03/rdf-tracking/#rdf-ns-prefix-confusion

From: Dave Beckett <dave.beckett@bristol.ac.uk>
Date: Thu, 24 May 2001 14:47:07 +0100
To: w3c-rdfcore-wg <w3c-rdfcore-wg@w3.org>
Message-ID: <21939.990712027@tatooine.ilrt.bris.ac.uk>

Previous threads can be followed from
  http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2001May/0087.html

I propose we resolve:

1. The current RDF/XML syntax uses the following attributes in the syntax:

     about aboutEach aboutEachPrefix
     ID bagID
     resource
     parseType
     -- List of RDF attributes (henceforth The List)

     The remaining concepts are not in the list because:
       a. Seq Bag Alt Property Statement
	 These are rdfs:Class-es and can never be used as attributes
       b. RDF Description   
	 Syntax only things that have no current use as attributes
       c. li _<n> subject predicate object type value
	 Not allowed to be used unprefixed according to the grammar

     Note Re: aboutEach aboutEachPrefix
       At present it is expected these will be removed from the
       specification although the WG has not addressed this yet.
       See thread at http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2001May/0123.html

2.  The grammar will be corrected to require namespace-qualification
    for all attributes for The List.  A namespace prefix MUST be used
    for these attributes, where the namespace prefix points to the
    RDF URI http://www.w3.org/1999/02/22-rdf-syntax-ns#

    The meaning of the attributes is defined by the appropriate RDF
    M&S sections and is not modified here.

    The changes to the grammar at
      http://www.w3.org/TR/REC-rdf-syntax/#grammar
    include modifying productions 6.6, 6.7, 6.8, 6.9, 6.11, 6.18,
    6.32, 6.33 to have rdf: added before all the attributes.  There
    are almost certainly other changes to the grammar, as well as
    changes throughout the rest of the document such as examples and
    in-text mentions.

3.  Unprefixed attributes are deprecated - they SHOULD NOT be used in
    the syntax from this date and WILL be forbidden in the next RDF
    syntax document.

4.  On input, unprefixed attributes from The List MAY be accepted.
    If accepted, these attributes MUST be handled as if they were
    written with a prefix as defined in #2.

5.  On output, all RDF attributes from The List MUST be emitted with
    a namespace prefix; where the prefix is defined as in #2.

6.  The grammar will be corrected to allow non-namespace
    qualified RDF elements (NOT attributes) when a default XML
    namespace is defined with an xmlns="..." attribute.

    Discussion: For example
      <Description xmlns="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
         ...
      </Description>
    is currently forbidden by production 6.3; it requires rdf:Description

7.  Unprefixed attributes not on The List have no meaning in RDF
    and MUST NOT be used to generate statements.   Applications MUST
    skip the element containing such attributes and generate no
    statements for the entire XML element and content.

I've tried to capture the concensus on deprecation but I'm unsure if
it comes across in the above.  Specifically, #3 and #4 seem to
clash.  Do we allow unprefixed attributes for backwards comp. at all
in future or forbid them in the future?

Dave
Received on Thursday, 24 May 2001 09:47:10 EDT

This archive was generated by hypermail pre-2.1.9 : Wednesday, 3 September 2003 09:35:51 EDT