This can be handled if the server:

1) Assigns an event id that is different from the if assigned to original event.
2) Uses the current time of the underlying systems as the event time.
3) Returns a NULL field for any values which are not available.

Clients must be able to deal with NULL values for mandatory fields but servers should only do this if there is some kind of problem with the system.

The Quality property is the Quality of the source variable and is not affected by problems with missing data. i.e. it should be Good.

I mentioned already during our meeting today that we defined something in Part 4 about missing event fields.
Here is what is defined in Part 4 -> 7.16.3 EventFilter

The SimpleAttributeOperand structure is used in the selectClause to select the value to return if an
Event meets the criteria specified by the whereClause. A null value is returned in the corresponding
event field in the Publish response if the selected field is not part of the Event or an error was
returned in the selectClauseResults of the EventFilterResult. If the selected field is available but
cannot be returned to Client then the Server shall return a StatusCode that indicates the reason for
the error. For example, the Server shall return a Bad_UserAccessDenied error if the value is not
accessible to the user associated with the Session. If a Value Attribute has an uncertain or bad
StatusCode associated with it then the Server shall return the StatusCode instead of the Value.

This definition clearly states that the server shall return a StatusCode instead of the value if the value is not available.

for fields that are supported, but not currently available a status code is returned

Added error code Bad_NoCommunication

Reviewed and accepted change in Boca meeting (after final editing in the meeting).