Body:
| (Origin*, Annotation*) |
Attributes:
...
A reference to an ItemDef as it occurs within a specific ItemGroupDef. The list of ItemRefs identifies the types of items that are allowed to occur within this type of item group.
Origin defines the source metadata, where applicable, for ODM items. Origin as a child element of ItemRef replaces the Origin attribute on ItemDef. The Origin element is based on the def:Origin element in Define-XML v2.1 with the Trace-XML v1.0 extension, but does not include the def:DocumentRef child element.
The ItemRefs within a single ItemGroupDef must not have duplicate ItemOIDs nor OrderNumbers.
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