...
After the job has modified the event it looks like: 
Now the value of the event is "set" or true.
Using Events in Triggers
The purpose of an event is to signal partial completion of a task and to be able to trigger another job which is waiting this partial completion. Task "t1" creates a file, sets an event and saves the file (which might take a long time.) Another task, "t2" only needs the on-line copy of the file so it can start as soon as the file is made, e.g.
suite x family f task t1 event foo task t2 trigger t1:foo == set |
The "= = set" part is optional since the value of the event is Boolean anyway.