Da Voismart Knowledge Base.
Send an arbitrary event to the manager interface

  UserEvent(eventname[|body]): Sends an arbitrary event to the manager
interface, with an optional body representing additional arguments.  The
body may be specified as a | delimeted list of headers. Each additional
argument will be placed on a new line in the event. The format of the
event will be:
    Event: UserEvent
    UserEvent: <specified event name>
If no body is specified, only Event and UserEvent headers will be present.