Substitution Group Wording in Structures

"All such members must have type definitions which are either the same as
the head's type definition or restrictions or extensions of it"


"An empty {substitution group exclusions} allows a declaration to be
nominated as the {substitution group affiliation} of other element
declarations having the same {type definition} or types derived therefrom.
The explicit values of {substitution group exclusions} rule out element
declarations having types which are extensions or restrictions respectively
of {type definition}. If both values are specified, then the declaration may
not be nominated as the {substitution group affiliation} of any other

In the second section it seems that even if both values are specified
elements of the same type as the head should be allowed as the substitution
group affiliation.  Am I reading something wrong here.  Is this just a
strict rule (specifying both extension/restriction = specifying all
extension/restriction/same) for simplicity?

Jeff Rafter
Defined Systems
XML Development and Developer Web Hosting

Received on Thursday, 7 June 2001 01:59:21 UTC