Reasons are managed under Kitchen Settings > Cancel/Pause Funnel Reasons (/admin/subscriptionreasons); each reason can apply to pauses, cancellations or both, and can require a written justification. They are shown in the admin pause/cancel modals and in the customer's own pause/cancel/request modals when Client Config > Order: Subscription > Show Subscription Pause Reasons / Show Subscription Cancel Reasons are set to Yes. The last reason given is displayed on the subscription page ("Cancellation reason" or "Pause reason" box) and the reasons are aggregated at /admin/subscriptionreasonstats.