In Unified Modeling Language (UML) sequence diagrams, you can show
operation signatures or message signatures of individual messages to visually
represent communication in interactions in Java™ or Enterprise JavaBeans™ (EJB)
applications.
You must have a sequence diagram that contains messages open.
To show an operation signature or message signature in a UML sequence
diagram, in the diagram editor, right-click a message; then click .
The operation signature or message signature of the message is displayed
in the name compartment.
Note: If the message has no arguments, the operation
signature of the message is displayed. If the global preference Show
Operation signatures instead of Message signatures is selected,
the operation signature of the message is always displayed.