Scheduler - Stacking of Overlapping Events

Do I understand it correctly that although there are three events in the screenshot you define six events?

Events are rendered in the in the order determined by the default sort order. You can also define a custom sort (and rendering) order as described here:
(https://doc.daypilot.org/scheduler/event-sorting/)

Yes, correct.

In the screenshot "diff_pos.jpg" there are four events of two groups. The first group "green triangle" is at line 0, the second one at line 1.

If I postion them at the same line "0", the first green triangle (left) event is covered.

Is this caused by the default sort order?

By default, the Scheduler uses the start date to sort events. If the start date is the same, the longer event goes first. If both dates are the same, the order can't be guaranteed.

But maybe it would be better to use an active area instead of another event to insert the triangle?

You mean, an active area inside the cell itself? If yes, then I would have a problem with showing the bubble of that active area. Because the cell is covered by the full crosshair (crosshairType: 'Full')

Ok, I see - the triangle belongs to a cell, not to an event.

Anyway, you should be able to control the layer by adjusting the sort order.

No, it belongs to an event.

You're suggesting to to use an active area instead of another event to insert the triangle. To what should this active area belong? Either to an event or a cell. Right now I'm using the event variante. If I would use the cell variante, than I would have a problem with the full crosshair, as I mentioned

Are there other types of active areas?

You can attach active areas to events and cells.

But as I understand it, you have a special event (displayed in a layer above another event) that is transparent and only contains an active area. So I'm wondering why you don't add the active area directly to the underlying event.