Exclusive transitions or dialogs
Exclusive dialogs are special forms of dialogs. They are also referred to as null or one-step dialogs. They consist of a single transition only. You can use them to go into a dialog, run only one transition, and use it to end the dialog immediately afterward.
Code
sample
<transition type="exclusive">
<source>
<transition-endpoint nameref="portlet1">
<event qname="eX"/>
</transition-endpoint>
</source>
<target>
<transition-endpoint nameref="portlet2">
<event qname="eX"/>
</transition-endpoint>
</target>
</transition>