UML sequence diagram - how to show a web service call
I recently started to model an application that makes extensive use of web service calls, and my customer asked me to include a UML sequence diagram to show the flow of calls in the system. This prompted me to wonder, "What is the correct way to show distributed systems (like a web service) in a UML sequence diagram?"
If this link is correct, in a UML diagram you show remote systems as actors.