Re: XML Schemas: Best Practices

[Curt Arnold <Curt.Arnold@hyprotech.com>]

I hope your are following the XHTML M12n thread since it is touching some of
these issues.

Another limitation or concept (depending on your point of view) of
substitution groups is that an element can only participate in one
substitution group.

The choice construct requires you to explicitly change the definition of the
containing element which may be in a schema you do not control.
Substitution groups allow you to implicitly change the containing element at
the definition of the contained element.