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Curt Arnold wrote:
>
> Another limitation or concept (depending on your point of view) of
> substitution groups is that an element can only participate in one
> substitution group.
I am not sure that I understand all the implications of this.
Let's take the Catalogue example. We created two elements, Book and
Magazine, and put them in the substitutionGroup with the abstract
element Publication:
<element name="Book" substitutionGroup="c:Publication"
type="c:BookType"/>
<element name="Magazine" substitutionGroup="c:Publication"
type="c:MagazineType"/>
Thus, anywhere <Publication> may occur, it may be substituted by
<Book> or <Magazine> (in fact, it must be substituted by one of these
elements since it is abstract).
<Book> and <Magazine> may "only" substitute for <Publication> and no
other element, since they may be in only one substitutionGroup. And,
this is limiting. Is that what you are saying? Anything else?
/Roger
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