On Wed, 31 Jul 2002, Ann Apps wrote:
> > A new version of the "Guidelines for implementing Dublin Core in XML"
> > document is available at:
>
> > Recommmendation 7 has been amended to state that:
> >
> > - the name of an "encoding scheme" associated with a property should
> > be
> > encoded as the value of an xsi:type attribute of the XML element
> > representing that property
> > - the names of "encoding schemes" should take the form of XML
> > Qualified
> > Names (QNames)
> >
> I guess this is 'correct' so the change has to be made. But I'm
> concerned how much code there is already out there which says
> 'scheme=' rather than 'xsi:type='. I assume this will apply only to
> XML and not to HTML, so HTML documents will still use
> 'scheme='?
Correct. These recommendations do not impact on current mechanisms for
encoding DC in HTML meta tags.
Yes, there is some existing use of 'scheme' in XML applications. I have
no real way of telling how much. 'Guidelines' are meant to be broken -
particularly before they are written! :-)
> Should the namespace used for the xsi:type always be a DC one?
> Eg should I use
> xsi:type=dcterms:LCSH and xsi:type=dcterms:W3CDTF
> or should I use
> xsi:type=loc:LCSH and xsi:type=w3c:W3CDTF
> (assuming those namespaces exist).
I would contend that scheme names in any namespace can be used in the
xsi:type value, but that for the majority of DC metadata the names will be
taken from the dcterms namespace.
> Following on from the above comemtn about 'scheme' I wonder if
> this document should say anything about 'legacy' code which was
> written according to earlier versions of these guidelines, or before
> the guidelines.
I am happy to add something acknowledging that existing instance metadata
may use other conventions, e.g. use of 'scheme' rather than 'xsi:type' and
that consuming applications may want to be fairly liberal in what they
accept.
> The examples in the document begin with XML schema
> declarations with no explanation. Is there an assumption that
> readers of an XML guidelines document will understand what they
> mean?
I guess so... :-)
> Perhaps this document should reference the 'Recommendations for
> XML Schema for Qualified Dublin Core' document.
We took the decision not to do this, partly because we weren't sure about
the final location (URL) for that stuff... nor for how long it might take
to get thru to recommended status.
> I think that the section on mixing DC metadata with other schemas
> could do with a bit more explanation about mixing schemas. The
> above document makes some rather categorical statement about
> compromising interoperability when mixing schemas in application
> profiles, whereas this guidelines document implies this is normal,
> acceptable encoding. [Actually I'm not convinced it does
> compromise interoperability - I assumed that applications which
> understand only the DC schemas will simply ignore other parts of
> the XML metadata.]
I'm interested to hear other's views on this... we can add a note of
warning if necessary?
Andy
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