Dropping a project
If you've decided not to work on a project any further, you can drop it completely. It disappears from your Active list in the sidebar, and its actions likewise stay hidden. Of course, you could just delete the project, but then you wouldn't have any record of it or its actions ever having existed. Keeping them around in a dropped state means you can go back and check on how often you give up on projects, check which actions you've completed regardless of whether they're from still-relevant projects, and so on.
There are several ways to drop a project: Select the project in the main outline, then use the Status control in the inspector to choose Dropped.
Select the project in the sidebar, then choose Dropped from the gear menu at the bottom of the sidebar.
Right-click or Control-click the project in the main outline or in the sidebar, then choose Dropped from the contextual menu.
To make a dropped project active again:
Choose Dropped from the view bar's project filter pop-up menu.
Find the project, then use one of the same techniques as above to set the project's status back to Active.