History description 2014-03-26: Lock all vaue sets untouched since 2014-03-26 to trackingId 2014T1_2014_03_26
description:
A service that actually happens, may be an ongoing service or a documentation of a
past service.
Historical note: in previous RIM versions, the event mood was captured as a separate
class hierarchy, called Patient_service_event, and later Service_event.