In terms of deciding what constitutes an event, the question has been raised whether or not it is relevant if the narrative voice is passive or active. An example of the former can be found in Iliad 16.168:

"Fifty ships had noble Achilles brought to Troy, and in each there was a crew of fifty oarsmen. Over these he set five leaders whom he could trust, while he was himself commander over them all."

The issue in cases like this is whether Achilles is actively appointing his leaders, thus making it an event, or if it is simply Homer providing exposition. So far, all events involving some sort of explicit action, regardless of their relative passivity, have been recorded; however, an official guideline might be useful.