If {HEAD ~ the link} to the event is selected by {TAIL ~ the user}, then that event is made the current event in the user interface and the other windows are updated accordingly 
If { HEAD ~ the link } to the event is selected by { TAIL ~ the user } , then that event is made the current event in the user interface and the other windows are updated accordingly
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH