You can specify the Message Kind on page 3 of the Message tab in a Message’s definition. You can specify the following kind of Messages:
•Complete: A Complete Message has a filled-in arrow head.
•Found: A found Message is denoted with a small black circle at the starting end of the Message.
•Lost: A lost Message is denoted with a small black circle at the arrow end of the Message.
•Unknown: Has a Closed arrow head.
It was not clear whether the end points of Lost/Found messages should be allowed to be left unattached at the Lost/Found end, so this has been supported. In cases where the message is to be drawn within an Interaction or some other containing symbol, the line will snap to the edges of the container and prevent the end point from being placed in whitespace. A Lost/Found Placement symbol has been provided to act as a line anchor point. It is hidden when a line has been connected.