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In a linked series of ODM files, the AsOfDateTimes of those files must occur in temporal order, and the DateTimeStamps in each file must be later than the AsOfDateTimes of the prior file.
The ordering for data elements can be asserted with the use of RepeatKey (eg StudyEventRepeatKey, FormRepeatKey, etc) attributes. Note that this is relative to the parent element, and is expected to follow Upsert semantics; the series of RepeatKey values are expected to be contiguous.
A data entity (like an item group) can be represented as a series of data elements. These elements can contain data for disjoint parts of the entity (properties and children), sequential changes to the same parts, or a mixture of the two.
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