W3C home > Mailing lists > Public > www-rdf-interest@w3.org > September 2000

RE: Namespace squatting: please don't

From: Jonathan Borden <jborden@mediaone.net>
Date: Sun, 17 Sep 2000 17:31:50 -0400
To: "Dan Connolly" <connolly@w3.org>
Cc: <www-rdf-interest@w3.org>, <jos.deroo.jd@belgium.agfa.com>
Message-ID: <001201c020ee$b0a65550$0201a8c0@ne.mediaone.net>
Dan Connolly wrote:

> > >
> > > So... like...
> > >
> > > Hey, You Kids, Get Off My Lawn!
> > >
> > > -- http://www.goddamn.com/content/lawn.cfm
> >
> >     Since you include a URI, is this an RDF assertion?
>
> Er... huh?

I was being a bit too obtuse (this is approximate but hopefully makes the
point):

(author, http://www.w3.org/1999/02/22-rdf-syntax-ns#instance, "Sergey
Melnik")
(authority, http://www.w3.org/1999/02/22-rdf-syntax-ns#, "Dan Connolly")
(derived-from, http://www.w3.org/1999/02/22-rdf-syntax-ns#instance,
http://www.w3.org/1999/02/22-rdf-syntax-ns#)

=>

(http://www.goddamn.com/content/lawn.cfm, "Dan Connolly", "Sergey Melnik")

This works because the particular namespace ends in neither a Letter or '_'.
Yet suppose the offending namespace is "http://www.w3.org" now the offending
resource is:

http://www.w3.orginstance and you no longer have rights to this name! You
cannot rightfully assert

(derived-from, http://www.w3.orginstance,  http://www.w3.org)

My point here is that the mapping of namespace qualified element names to
URIs as specified in M&S is broken (i.e. simple concatenation won't do). The
'hack' that RDF uses is to constrain the namespace URI to end in neither a
Letter or '_'. The problem is that other specs such as XLink do not so
constrain the namespace URI, and it is intended to map XLink to RDF. This
needs fixin'.

>
> Yes, I am saying that RDF schema can be used to state
> the intended use of namespace names.

Good. I was hoping this was the case. I have placed a proposal to map XML
namespace qualified element names to URIs at:
http://www.openhealth.org/RDF/QNameToURI.htm

I believe that if such a mapped URI is equated to the element name, this
would have the desired effect of limiting who can create new element names
within a given namespace.

For example, Jos De Roo states:

>Jonathan Borden wrote:

>> It is logical that the owner of a namespace (whatever that
>> means) may restrict the ability of others to add elements
>> to the namespace but where is this precisely specified?

>I don't know, but what I do know is that when there is an RDFS
>resource out there, I can dereference it's URI and use that
>content in my proof engine to avoid illicit term usage.
>Thanks Jonathan, it is a very important issue for our RDF
>based medical imaging services!

	Yes but are you using elements within some DICOM namespace for your medical
image representations? Suppose the DICOM namespace URI does not end in '#'.
Given the M&S definition, how can you properly dereference the DICOM element
name into the RDFS Property (or Class etc.)?

IMHO one of the problems RDF has had in receiving widespread acceptance
among the XML community is that it is too 'self contained'. More effort
needs to be directed at interoperability with the rest of the XML standards
and specifications.

Jonathan Borden
The Open Healthcare Group
http://www.openhealth.org
Received on Sunday, 17 September 2000 17:23:30 GMT

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