They are the list of reasons a customer must choose from when they pause or cancel a subscription from their account (and that your staff choose when doing it in the admin). Each reason has a name, can require a free-text justification (with an optional title for that text box), can be active or inactive, and can be used in the pause flow, the cancel flow or both.

Manage them under Cancel/Pause Funnel Reasons (/admin/subscriptionreasons). The page lists Active and Inactive tabs with columns ID, Name, Need Justification? ("Yes – <title>" or "No") and In use ("Pause Subscription", "Cancel Subscription" or "Pause & Cancel Subscription"). Buttons: How it works (video), View Stats and Add new.