We had some discussion on the list about making some of the subelements
global, so that they can be used in other schemas. We didn't want to hold
up version 3.0 any longer, and are doing some testing on how this can be
done in the schema. We plan to issue another version with minor changes to
allow for global subelements in the near future. These changes will not
have any affect on records created using 3.0.