Marking Entry as Completed
Some users wanted to be able to mark items as having been completed, over and above what the card status already allowed you to signify. For example, one user wanted to change the status of several entries to be “mailed” and others to “airmail” when first organising her list, but then be able to mark as completed once the cards were actually sent.
To mark an item as completed, (or several items if you have selected more than one), select the item(s) and right-click (Control-click) to show the context menu. Then select Mark as Completed.
Items that have been marked as completed will then have a little tick to the right of the name.