xml-dev - Re: URNs as SYSTEM IDs

[Joe English <jenglish@flightlab.com>]

Simon St.Laurent wrote:
> At 02:57 PM 11/22/00 -0500, Norman Walsh wrote:
> >/ "Simon St.Laurent" was heard to say:
> >| In common practice, that's meant using URLs, typically HTTP-based URLs.
> >| Validating (and some non-validating) XML parsers tend to report errors when
> >| they can't retrieve the content referenced by a SystemLiteral, since
> >| effectively it means that they can't validate the document.
> >
> >They can retrieve the content if they have some practical entity
> >management system in place, such as OASIS TR9401 Catalogs (through,
> >for example, a SAX entityResolver).
>
> The problem is that this kind of infrastructure is barely deployed, and
> many developers don't even know of its existence.

PUBLIC ID resolution doesn't need to be universally deployed
for it to be useful.  In many scenarios, out of all the software
that might be used to process an XML document, only one -- the
document's author's validator -- really needs PUBLIC ID support.
All other document consumers should be able to ignore the
<!DOCTYPE ...> declaration entirely as long as the DTD
makes no essential InfoSet contributions.



--Joe English

  jenglish@flightlab.com