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RDF M&S use of XML namespaces for attributes

From: Dave Beckett <D.J.Beckett@ukc.ac.uk>
Date: Fri, 25 Jun 1999 18:20:19 +0100
To: www-rdf-comments@w3.org
Message-ID: <10446.930331219@myrtle.ukc.ac.uk>

In RDF M&S attributes are defined for RDF elements that are only used
on these elements, for example 'about' on the description element.
These attributes seem to be expressed in different ways in the document.

For example, in the unlabelled last example in section 7.4 it starts:

<rdf:RDF
    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
    xmlns:dc="http://purl.org/metadata/dublin_core#"
    xmlns:dcq="http://purl.org/metadata/dublin_core_qualifiers#">
    <rdf:Description about=
    "http://www.dlib.org/dlib/may98/miller/05miller.html">
...

Compared to the start of the next example in 7.5

<rdf:Description
    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
    xmlns:dc="http://purl.org/metadata/dublin_core#"
    xmlns="http://www.w3.org/TR/REC-mathml"
    rdf:about="http://mycorp.com/papers/NobelPaper1">
...

In example 2, why is the rdf: needed in rdf:about since 'about' is
defined as an attribute of the rdf:Description element? [prod. 6.7]

Example 2 has a default namespace which isn't used (at this part of
the example) however example 1 which has NO default namespace
contains the un-namespaced attribute, however:

XML Namespaces document, section 5.2 says

     A default namespace is considered to apply to the element where
     it is declared (if that element has no namespace prefix), and to
     all elements with no prefix within the content of that
     element. If the URI reference in a default namespace declaration
     is empty, then unprefixed elements in the scope of the
     declaration are not considered to be in any namespace.  Note
     that default namespaces do not apply directly to attributes.

so the last sentence implies in these examples that the default
namespace in example 2 doesn't apply to any attributes.


So in summary - what are the answers to these questions

  Is rdf:about a valid attribute on an rdf:Description element?

    [I think no]

  Is about a valid attribute on an rdf:Description element?

    [I think yes]

similar arguments and questions to aboutEach, bagID etc.



Dave

--
UK Mirror Service - http://www.mirror.ac.uk
Received on Friday, 25 June 1999 13:20:27 GMT

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