About this task
A group can be either of the following compositions:
- Sequence
- All objects in the group can appear in the data.
- Choice
- Only one of the objects in the group can ever appear in the data.
Both compositions of group can be either global
or local.
- A global group has a name. Using a group reference,
it can be reused across messages, elements, types, and other
groups.
- A local group has no name. In the editor, it is
shown as either sequence or choice. It is
available only where it is declared and cannot be reused.