...
The original metadata template specification did not envision the possibility that assertions that templates are in error might themselves be made in error. And thus there was no mechanism to restore templates mistakenly asserted to be in error. Thus the "event view" has improved the flexibility of RT.
One disadvantage to this approach is that to query "good" data in the RTS, the query must check disjunctively for the values I and R in the EC parameter. Alternatively, we could add a flag to the templates themselves that determines whether they are valid. This flag would be set to true upon insertion and revalidation, and to false upon invalidation. The disadvantage to that approach is keeping the flag in synchronization with the information in the metadata templates in the RTS.
The EC parameter
The EC parameter takes the same values as the original E parameter except for the value I (insertion). It is not a required field in the case of a template insertion or revalidation. It would be required for any metadata template with an EV parameter with value X.