Creating Events

So I did a few dungeon runs with guild members this weekend and they created events I was able to claim participation for.

I was wondering what the criteria are for that?  Someone mentioned it needs to have 1 leader and at least 3 participants to be eligible?  Do you need to be of the Elder rank to create the event?  What if one of the people doesn't bother to claim participation, is the event invalidated and the other participants don't get credit?

Thanks!

From the "Lead an Event" page: "Welcome to the Leadership System. The Leadership system is used to log activities completed by a Leader (You) and 3 or more other Gaiscioch or Tuatha members for a total of 4 Gaiscioch or Tuatha Members. The person logging the event must be the person leading the event." You must be a Lorgair or higher to create events. I am fairly certain the event counts even if everyone does not claim participation.