Re: [xml-dev] An approach to let XML 2.n resources hold multiple entities

Micah Dubinko wrote:
>
> 
> Since there are multiple versions of some vocabularies that can't be
> distinguished by the namespace, only by the DOCTYPE, something like this
> would help processors figure out what to do.

If this is an accurate statement of the problem, then I think that there 
are solutions out there. There are three separate issues:

  * multiple "related" namespaces
  * multiple versions of a namespace
  * multiple schemas for a single logical namespace

If you model your versions as different namespaces altogether, then you 
have no problem, just use different namespace declarations.

If you want to have a concept of multiple versions, then you could add a 
"version" attribute to your namespace and figure out what version you're 
dealing with through that.

If you want a single namespace and multiple schemas (whether for 
versioning or otherwise), you can use the XML Schema SchemaLocation 
attribute...or equivalent for other schema languages that have such a 
concept.

The current concensus view is that document types/vocabularies are 
distinct from schemas. The DOCTYPE declaration conflated them in a way 
that was harmful.

  Paul Prescod