...
>The valid status are: Completed, Failed, Future, In Progress, Missed,
>Pending, Restarted, Severed, Started, Uncertain but there is nothing about
>(?).
...

In cases like these, a search of the IBM database is in order:
 +"query event" +status +question
turns up two hits, which explain that the question-mark status involves
uncertainty in the loss of communications.

Your software levels weren't included in your posting, so we can't
gauge whether this is something that prevails at those levels.

    Richard Sims   http://people.bu.edu/rbs