2.5.7.4 ShowMessage Action

If present,<35> the ShowMessageAction field specifies that a message box can be displayed on each session where this user is logged on to the local machine.

 <!-- ShowMessage -->
 <xs:complexType name="showMessageType">
    <xs:complexContent>
       <xs:extension base= "actionBaseType ">
          <xs:all>
             <xs:element name="Title" type="nonEmptyString"/>
             <xs:element name="Body" type="nonEmptyString"/>
          </xs:all>
       </xs:extension>
    </xs:complexContent>
 </xs:complexType>

Title: If present, this field contains a nonempty string for the caption of the message box.

Body: This field is not optional and contains a nonempty string for the contents of the message box.