Event Mark Tool
This tool is used to make a Event Mark over the track to set an automatization. There is an example of the process in the figures shown below. When the aircraft passes by the point created, an event is triggered and it can be used to start a set of actions (start an automation).
Event Mark Symbol
Clicking in Setup, in the subsection of automations, you can sign in the automations menu to link one event to one event mark following the next steps:
Firstly, you have to create a new event.
When the union is finished, the event mark has changed its symbol, as you can see in the last figure.