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RE: Possible issue: XML DOCTYPE declaration -- should the PUBLIC identifier be a URN?

From: Thompson, Bryan B. <BRYAN.B.THOMPSON@saic.com>
Date: Wed, 8 Oct 2003 12:15:06 -0400
Message-Id: <D24D16A6707B0A4B9EF084299CE99B390674D4BF@mcl-its-exs02.mail.saic.com>
To: Paul Grosso <pgrosso@arbortext.com>, "Thompson, Bryan B." <BRYAN.B.THOMPSON@saic.com>, www-tag@w3.org
Cc: "Bebee, Bradley R." <bebeeb@US-McLean.mail.saic.com>, Guy.A.Lukes@frb.gov

Paul,

I choose the words '"as if" it were a universal resource name' to indicate
that it had similar semantics, not that it was, in fact, conformant to the
URN specification.  Thanks for the [2] and [3] references, but I still think
that this might be clarified, e.g., in the XML specification.  Basically
this
'catalog' approach and the URN approach are partially overlapping.  It would
be nice to see this addressed.

-bryan

-----Original Message-----
From: Paul Grosso [mailto:pgrosso@arbortext.com] 
Sent: Wednesday, October 08, 2003 10:55 AM
To: Thompson, Bryan B.; www-tag@w3.org
Cc: Bebee, Bradley R.; Guy.A.Lukes@frb.gov
Subject: Re: Possible issue: XML DOCTYPE declaration -- should the PUBLIC
iden tifier be a URN?


At 10:16 2003 10 08 -0400, Thompson, Bryan B. wrote:

>I just noticed that the XML 1.0 Recommendation (Second edition) does 
>not state a requirement that the public identifier in a DOCTYPE 
>declaration must be a URN, e.g.:
>
>-- snip from http://www.w3.org/TR/REC-xml#NT-ExternalID --
>
>[Definition: In addition to a system identifier, an external identifier 
>may include a public identifier.] An XML processor attempting to 
>retrieve the entity's content may use the public identifier to try to 
>generate an alternative URI reference. If the processor is unable to do 
>so, it must use the URI reference specified in the system literal. 
>Before a match is attempted, all strings of white space in the public 
>identifier must be normalized to single space characters (#x20), and 
>leading and trailing white space must be removed.
>
>-- end snip --

 . . .

>So it is pretty clear that the public identifier is not a URN per 
>RFC2396.

Correct, it does not have to be a URN.  It has to be a public identifier
whose syntax is defined in the XML spec [1].

>At the same time, it is being used "as if" it were a universal resource 
>name

Huh?  Says who, where, and what does this mean?  The paragraph from the spec
that you quote above defines what may be done with a public identifier, and
"use the public identifier [in some unidentified way] to try to generate an
alternative URI reference" does not mean "use as if it were a URN" to me.

For example, see the various OASIS Catalog specs [2,3] if you are not
already 
familiar with how public identifiers are and have been used for over a
decade.

>and the XML processor is encouraged to identify a URI that may be used 
>address the XML grammar declared by the DOCTYPE declaration.

I'm not sure I understand the issue here at all.

paul

[1] http://www.w3.org/TR/REC-xml#NT-PubidLiteral
[2] http://www.oasis-open.org/specs/tr9401.html
[3]
http://oasis-open.org/committees/entity/specs/cs-entity-xml-catalogs-1.0.htm
l
Received on Wednesday, 8 October 2003 12:15:20 GMT

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