At 1:39 PM -0700 06/03/2004, Jim Lyon wrote:
4. [Doug] We should require that a conforming document never have any
references to a namespace other than ...:marid-1 (or possibly
...:marid-*).
Allowing references to as-yet-undefined namespaces is an important part
of the extensibility. As extensions are defined, it allows publishers
to write documents using the new extensions, yet remain compliant with
the current version. Without this, it would be suicidal for a publisher
to take advantage of a new extension -- his document would be seen as
invalid by any implementation that hadn't yet been updated to understand
the extension.
As an aside, one of the options is to use urn:ietf:params:xml:schema:marid:m1,
rather than marid-1. Some folks might find it easier to extend underneath
the schema with this format; it doesn't change the extensibility
considerations,
at least as I read them.
I do think the extensibility considerations will need more work.
This requirement:
"A program MUST ignore any element or attribute whose meaning it does not
understand." is very clear, and I appreciate that kind of clarity. There are a
lot of consequences to that choice, though, that probably needs to be at
least sketched here. A pointer to a separate document which describes
how to manage extensions with that design constraint would also be
great, if one were available. RFC3735 may be a useful model. An
informational
reference to an I-D along those lines would probably be okay (given the
advice might not be done in time for publication).
regards,
Ted Hardie