The Manual entry is here:
Scroll down the the page about two thirds, to "Special Conditions"
Else is an Event that follows directly after the event that triggers it, not as a sub-event.
If the triggering event does not run, the else will run instead.
To create one, you have to clcik on the far left of the event you want to add it after. Not in the middle on the event text, but left of the event icon, and in that menu choose "Add" it will be at the bottom of that sub-menu.
It should turn red if it's used in the wrong place. (IE you delete the triggering event.)