The Releases Settings dropdown on Releases > Gantt includes two options: 

1. Show/Hide Shipped releases
2. Show/Hide Parking lots

Showing/Hiding shipped releases makes sense since a shipped release is date-bound, so a Gantt view can display it. But Show/Hide Parking lots does nothing, because PLs don't have release dates. 

These two options appear a couple other places in the product (reports, roadmaps) where they both affect the user's view, but in this case the parking lot option is a little weird to include. 

As a user, I would expect every setting option in a screen in Aha! to do something. Parking lot viewing will never do anything in a Gantt chart, so it will only confuse users. We should hide that option.