A completion action is a type of action that allows marketers to define what happens after a prospect completes a specific activity, such as submitting a form, clicking a link, or opening an email. One of the capabilities of a completion action is to remove a prospect from a list. This can be useful for managing list membership, suppressing prospects from future sends, or moving prospects to different lists based on their behavior. A completion action cannot send a list email to a prospect, increase a prospect’s grade, or adjust a prospect’s account field2. References: 2: Completion Actions