[ubl-ndrsc] Release Note Wording: Extensions and Ur

[Arofan Gregory <arofan.gregory@earthlink.net>]

Folks:

Below please find proposed wording for inclusion in the Release Notes
accompanying the LCSC package.

Cheers,

Arofan

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A Note on the UBL Extension Methodology
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The UBL TC has not yet come to a final decision on all the details of the
extension methodology to be followed by those using and customizing the UBL
core libraries. It is anticipated that there will be a need for users to
customize the core library, however, and much work has been done in this
area. The following points should be borne in mind during review of this UBL
Library release, as being probable features of future releases:

(1) All customizations (extensions and restrictions) will utilize XML
namespaces owned by the customizing user, into which the core UBL libraries
will be imported and referenced.

(2) All extensions and refinements will be expressed as XSD extensions in
the resulting XML schemas.

(3) The business need for extensions and refinements will be described using
a "context mechanism" based on that found in the UN/CEFACT Core Components
Technical Specification, and earlier in the ebXML Core Components work. This
mechanism provides for a rules language that lets machines determine the
appropriateness of a specific extension for a given business purpose.

(4) An "Ur Library" of XML types will be published in future as part of the
UBL deliverables, in its own set of namespaces, from which everything in the
UBL library will itself be a refinement. This should have little or no
effect on the direct use of the document types and components found in this
library release - they will have the same types and names - but will affect
how they are expressed in the schemas. The reason for having such a
mechanism have to do with the ability to express some types of
customizations within the capabilities of XSD syntax.

Those interested in further understanding of the anticipated extension
methodology should see the whitepapers found at the naming and Design Rules
section of the UBL portal (www.oasis-open.org).