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Re: Talked to the xml.gov people

From: Paul Prescod <paul@prescod.net>
Date: Tue, 27 May 2003 12:48:21 -0700
Message-ID: <3ED3C105.2040409@prescod.net>
To: Norman Walsh <Norman.Walsh@Sun.COM>, www-tag@w3.org

Norman Walsh wrote:
> ...  Or to put it another way, you can do
> | something with this:
> |
> | SYSTEM "http://www.w3.org/2001/XMLSchema"
> |
> | that you _cannot_ do with this:
> |
> | PUBLIC "urn:uuid:89793274983729473298473928"
> |
> | To me, that IS a difference and a significant one.
> 
> Uhm. What exactly can you do with the former that you can't do with
> the latter?

Given only the two strings, a modern operating environment and no more 
information, you can dereference one for research purposes and cannot 
the other. In order to dereference the second one you either need extra 
information (e.g. a catalog) or rarely-available software (e.g. a 
URN-aware distributed naming service). The rarely available software 
would just retrieve the missing information for you...

If you want to be simplistic, you could rephrase this as: you can "click 
on" the first one and it will probably return you useful information. 
The latter is quite unlikely to. From a programmer's point of view it is 
like associating the documentation with the code through a link. But the 
"code" happens to be an identifier and the "documentation" happens to be 
a web page.

I've seen some URN schemes proposed that allow URNs to embed HTTP URIs 
and I think that they represent a reasonable compromise.

  Paul Prescod
Received on Tuesday, 27 May 2003 15:48:30 UTC

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