schema extensions policy

["Bob Stayton" <bobs@sagehill.net>]

I'm following up on this action item:

 k.  Bob to research how we decided to handle schema extensions.

The only policy I found was from November 2010: 

DocBook Technical Committee Meeting Minutes: 17 November 2010
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...

6.  Namespace usage policy

The committee agreed that the TC cannot police efforts by
users to add elements to the DocBook namespace in their
local applications.  They just should not call it DocBook
if they do.

The committee is proposing the following text submitted by
Norm to be included in the DocBook documentation:

"DocBook is used throughout the world. As one would expect in such a
broad context, DocBook is often customized to satisfy the requirements
of specific organizations or projects. The DocBook TC encourages such
customization and works hard to make sure that the schemas are as
amenable to customization as possible.

When customizers add new elements to DocBook, they often place those
elements in the DocBook namespace (http://docbook.org/ns/docbook).
There is historical precedent for this approach as DocBook's history
pre-dates namespaces and even XML. Even without precedent, users would
almost certainly encourage customizers to use the same namespace. In
many cases it simplifies authoring and almost always simplifies the
training of new authors.

However, a new element introduced into the DocBook namespace by a
local customization is not officially part of DocBook. Only the
DocBook TC can introduce new elements into DocBook officially by
publishing a new version of the standard with those elements.

That means that the practice of adding new elements comes with a cost:
the potential for confusion among authors familiar with different
customizations and the costs associated with resolving any conflicts
between interchange partners.

The DocBook TC encourages customizers to think carefully about these
costs and weight the potential tradoffs between unofficially adding
elements to DocBook and using elements in their own namespace with
care."

ACTION: Norm to incorporate this into the official docs with
appropriate links to the "If you change DocBook, it's not
DocBook any more.


Bob Stayton
Sagehill Enterprises
bobs@sagehill.net