UML25 — Location: Pg. 615, Figure 17.4.3: Semantics, Sub-clause: Messages

his clause states, “A lost Message is a Message where the sending event occurrence is known, but there is no receiving event occurrence. We interpret this to be because the Message never reached its destination.”
The semantics described in the second sentence seem unnecessarily strict. Additionally, this interpretation for a lost Message is inconsistent with the interpretation of a found Message described in the next paragraph: “We interpret this to be because the origin of the [found] Message is outside the scope of the description.” The semantics of a lost Message should be similar.

Proposed Resolution:

Change the second sentence in the excerpt to read: “We interpret this to be because the destination of the [lost] Message is outside the scope of the description.”

Change the second sentence in the excerpt to read: “We interpret this to be because the destination of the
[lost] Message is outside the scope of the description.”.