The event mechanism is only provided for extended tasks and can be used to communicate binary information that synchronize these tasks on asynchronous events. Each extended task owns a set of events, that can be triggered by other (basic and extended) tasks or by ISR of category 2.
The typical behavior of an extended task is to wait for asynchronous events calling the OS service WaitEvent(). This service usually blocks the task until an event arrives. After servicing the event, the task calls again WaitEvent() to wait other events.
Events can be set only if the task is not in the suspended state. This seems to suggest that an extended task should never be in the suspended state.