CORBA35 — Section 22.2.4.6 interface RelativeRoundtripTimeoutPolicy

[..] It is used to indicate the relative amount
of time for which a Request or its corresponding
Reply may be delivered. After this amount of
time, the Request is cancelled (if a response
has not yet been received from the target) or
the Reply is discarded (if the Request had
already been delivered and a Reply returned from
the target) [..]
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Question:

• What is the precise meaning of "Request is
  cancelled"?

Does it mean that client ORB just gives up or
does it mean that client tries, in kind of best
effort semantics, to cancel request on server?

If this cancellation fails, how will client user
be informed about this? By a minor code in
thrown Timeout exception?

Is it possible to clarify this?