xml-dev - Re: URNs as SYSTEM IDs

[Norman Walsh <ndw@nwalsh.com>]

/ Michael Mealling <michael@bailey.dscga.com> was heard to say:
| > that dereferencing is somewhat, well, variable.  Using URNs - when there
| > isn't a whole lot of infrastructure for processing them - strikes me as
| > foolhardy, but I can see where they might be attractive from an abstract
| > perspective, at least.
| 
| Yep. Considering that what XML technology uses as its PUBLIC id would be
| considered a SYSTEM id by SGML.

What do you mean? XML 1.0 has both PUBLIC and SYSTEM identifiers and they
have essentially the same meanings. XML requires the SYSTEM identifier
to be present and mandates that it be a URI.

| There will be several cases where
| a URI used as the SYSTEM id is not resolvable via standard, globally
| available means.

That's why we need entity managers. Even if the SYSTEM id is a
straightforward URL, it may be 404.

                                        Be seeing you,
                                          norm

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