The table below lists the elements of UML 2.0 sequence diagrams that are available using the Tool Palette.  

UML 2.0 sequence diagram elements  

Sequence diagram can contain shortcuts to the other diagram elements. However, shortcuts to the elements that reside in the other interaction diagrams are not supported. 

Interaction diagrams, represented in the Model View, display a number of auxiliary elements that are not visible in the Diagram View. These elements play supplementary role for representation of the diagram structure. Actually, these elements are editable, but it is strongly advised to leave them untouched, to preserve integrity of the interaction diagrams.