URIs and namespaces summary

[Erik Hennum <ehennum@us.ibm.com>]

Hi, Namespace Enthusiasts:

I thought it might be useful to capture our current thought so that we can correct instead of recover the thought when the OASIS rules arrive.

The accepted namespaces proposal provides the background:

http://lists.oasis-open.org/archives/dita/200411/msg00006.html
http://lists.oasis-open.org/archives/dita/200410/msg00015.html

Below, I'll use "OASIS_DITA_Base" as a placeholder for a base URL assigned to DITA by OASIS.  For the purpose of concrete examples, I'll use "http://dita.oasis-open.org" with recognition that, too, is still just a placeholder.

For a physical schema file, the proposed convention is:

OASIS_DITA_Base/Schema_Type/Release_Identifier/Filename

The Release_Identifier can be "latest" to indicate the most recent release.

as in:

http://dita.oasis-open.org/dtd/1.0/concept.dtd
- The DTD definition of the concept document type in the null namespace
for the 1.0 release.

http://dita.oasis-open.org/dtd/1.0/concept_ns.dtd
- The DTD definition of the concept document type in the namespace of 
the concept document type for the 1.0 release.

http://dita.oasis-open.org/dtd/latest/concept.dtd
- The DTD definition of the concept document type in the null namespace
for the most recent release.

http://dita.oasis-open.org/dtd/latest/concept_ns.dtd
- The DTD definition of the concept document type in the namespace of 
the concept document type for the most recent release.

http://dita.oasis-open.org/xsd/1.0/concept.xsd
- The XML Schema definition of the concept document type in the null 
namespace for the 1.0 release.

http://dita.oasis-open.org/xsd/1.0/concept_ns.xsd
- The Schema definition of the concept document type in the namespace 
of the concept document type for the 1.0 release.

http://dita.oasis-open.org/dtd/latest/concept.xsd
- The Schema definition of the concept document type in the null namespace
for the most recent release.

http://dita.oasis-open.org/dtd/latest/concept_ns.xsd
- The Schema definition of the concept document type in the namespace 
of the concept document type for the most recent release.

For namespaces, the proposed convention is:

OASIS_DITA_Base/xmlns/Name_Category/Named_Thing/Major_Version_Identifier

In DITA 1.0, the Name_Category can be

"architecture" for properties of the DITA architecture
"doctype" for the document types that populate the architecture

The Major_Version_Identifier increments only to reflect fundamental changes in the named thing.  As such, the major version identifier is not the same as the release identifier for the schema implementation.  For instance, the 2.0 version of the XML Schema grammar files could retain the 1.0 DITA namespace for the concept document type.

The Named_Thing can be omitted where the Name_Category is sufficient.

For example:

http://dita.oasis-open.org/xmlns/architecture/1.0/
- The namespace of the DITAArchVersion attribute

http://dita.oasis-open.org/xmlns/doctype/concept/1.0/
- The optional namespace for the concept document type and its elements

Note that, because DITA provides a modular type hierarchy, the DITAArchVersion attribute indicates the version number of the architecture and not the document type.  In principle, document types could undergo major changes independently of each other and the DITA architecture. 


Thanks,


Erik Hennum
ehennum@us.ibm.com