This is the reference time based on which the extraction program will retrieve data for only those patients whose records have been created/updated after the reference time.

When a Patient is specified, the extraction program needs to only extract the data for a specific patient.If not specified, the extraction program will evaluate all consented patient records based on the reference time to identify the ones that have changed and need to be extracted.

The results of the extraction would provide the data for each patient whose data has been created/updated based on the referenceTime. This data will be in the form of a Bundle which has all the resources that are pertinent for each patient whose data has been extracted.

A list of hints and warnings about problems encountered while extracting the data. These might be show to the user as an advisory note. Note: if the extraction cannot be performed at all, then the operation should fail, and an OperationOutcome is returned directly with the failure, rather than using this parameter.