Re: What to do given both SYSTEM and PUBLIC?

On Wed, 19 Feb 1997 12:09:59 -0500 David Durand said:
>At 11:08 AM -0500 2/19/97, Steven J. DeRose wrote:
>>At 12:52 PM 02/18/97 -0800, Joe English wrote:
>>> (someone asked):
>>>> * what to do if you are given both and the resulting files are
>>>>   different

(Joe English)
>>>This means that somebody somewhere has made a mistake.
>>>We don't need to specify error recovery in this case.

(Steven J. DeRose)
>>I'll buy that; but you'll likely never *discover* the error, since
>>if you successfully resolve one ID it is unlikely you'll bother with
>>the other.

(David Durand)
>    It means that authors who intend to use both SYSTEM and PUBLIC are
>duty-bound to either use (and test) a programmatic solution that ensures
>they are identical, or must test the document with both public-preferred
>and SYSTEM-preferred resolution in place.

What on earth are you guys *talking* about??!!

Why on earth would it be an error?  Are you seriously suggesting that if
Peter Flynn's TEI Lite documents point the user to a copy of the TEI
Lite DTD on Peter's server in Ireland, but my local catalog file points
the XML processor to a copy on my hard disk, and the XML system finds it
there, that Peter and I have together committed an error?  The URLs
http://www.ucc.ie/curia/dtds/teilite.dtd and
file:///sgml/public/tei/derived/teilite.dtd are certainly not the same,
and don't point to the same file.  But they are certainly both copies of
the TEI Lite DTD, and I don't see why anyone at all, let alone the three
normally awake people I've just quoted, should think it's an error for
the public identifier and the system identifer to point at different

I thought part of the point of public identifiers was to make it
possible to detect the case in which you don't need to (re-)transmit
the DTD because the recipient of the document instance already has
it?  Or are we planning to use this method to push up the byte count
of SGML flowing across the Web?  All those thousands of copies of
ISO Latin 1, ISO Pub, ISO Num, etc.,...

What gives?

-C. M. Sperberg-McQueen
 ACH / ACL / ALLC Text Encoding Initiative
 University of Illinois at Chicago