It is a multi-select with Pause Subscription and Cancel Subscription. A reason ticked for Pause appears in the pause pop-up; ticked for Cancel it appears in the cancel pop-up; ticked for both it appears in both. At least one must be selected — saving with none returns The "Where this reason will be used" field cannot be empty. The list column In use summarises the choice, and the stats page shows the same as Paused / Canceled labels.