Hello,
sorry I forgot to change the subject in my letter.
> > So, to merge DCMI metadata, which identifications are we
> > allowed to use?
>
> While not explicitly stated (maybe it should be?) it's a
> reasonable assumption that the DCAM will use the same merging
> methodology as RDF, i.e., merging URIs based on
>
> http://www.w3.org/TR/rdf-concepts/#section-Graph-URIref
>
> "Two RDF URI references are equal if and only if they compare
> as equal, character by character, as Unicode strings."
>
> subject to a number of encoding rules.
Thanks for the clarification.
I think, it would be a good idea to state the merging methodology
explicitly.
I am not sure, however, that using the RDF concepts would be a best option,
one reason being that
http://www.w3.org/TR/rdf-concepts/#section-Graph-URIref
refers to RFC 2396 for URIs which has been obsoleted by RFC 3986 for URIs
and superseded by RFC 3987 for IRIs.
The other reason is that for me it is not immediately obvious if this
defines the same identity as the "Namespaces in XML 1.0 (Second Edition)"
(http://www.w3.org/TR/REC-xml-names/), which probably would be desirable.
In any case, the latter document deprecates relative URIs for namespace
declaration, and given the rigidity of the identification, relative
references (w.r.t. the base of the URI of the given document) as attribute
values might cause problems for URIs that are used as resource identifiers
as well. But this probably can be left to the consideration of DC-XML.
> So, of course a certain level of care must be taken when
> designing/using URIs.
>
> Also, nothing forbids an application to make certain guesses
> regarding equivalence beyond what is required by the RDF model.
These guesses (or the need for them?) are what worries me, I presume.
All the best
Thomas
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