This is a sideways view of the rack after I took the cups and saucers down. It was a good idea as they (and the rack) were d-u-s-t-y. (How did that happen?)
Here's a view of one of the saucers standing in the groove. You can also see the small nails that the handles of the cups hang on.
The rack is made with a good design because there are two doors to the left of the rack that we use frequently and we've never had any trouble with the saucers or cups jiggling out of place.
Hope this helps, Katie!