RE: [ubl] Discussion of substitution groups

["CRAWFORD, Mark" <MCRAWFORD@lmi.org>]

 >	I remember we discussed it in Hong Kong
>	and decided we need the minor version
>	namespace changes.

But when we discussed this in Hong Kong, we didn't talk about
substitution groups being required to support it.
	 
>	I have seen the problems you get when 
>	the minor versions don't have namespace
>	changes and they are highly regretable. I'd
>	hate to think of not learning at all from 
>	history.

Please provide details.
	 
>	Then of course there is the option that we
>	don't have minor versions and that seems
>	a catastrophic departure from all UBL has
>	achieved so far (IMO).


I am not suggesting we don't have minor versions, only that namespace
versioning of the minor versions is an unnecessary overhead that we
should avoid.  We have eliminated this in CEFACT for this and other
reasons.  Also remember, we are a model driven solution.  We have a
library that details our content models.  When a BIE changes, a new BIE
is created.  Why should we have different type definition rules for the
derived BIE?  Exactly what is gained by using type derivation rather
than just defining a new type that replaces the old in our schema?

Mark