When Requires Justification? is on, selecting that reason in the pause/cancel pop-up reveals a text box the customer (or admin) fills in. Justification title is the label above that box; the hint reads "Leave empty if you want a justification field without title" — with no title, the reason's own name is used as the label of the answer.

The typed answer is stored with the subscription's pause/cancel record and shown in the Answer column of the reason's stats pop-up and on the subscription's admin page; it is also passed into the pause/cancel notification fields. In the reasons list the column Need Justification? shows "Yes – <title>".