PayPal doesn’t tell s2Member what those fields are.
The replacement codes available for the notification are described below the box where you enter the URLs. [hilite path]Dashboard -› s2Member® -› API / Notifications -› Payment Notifications[/hilite]
Those replacement codes for stree_address and country are examples of ones that would be available if you had them as custom profile fields in s2Member, but that’s independent of what the user enters during checkout over at PayPal.
Custom Registration/Profile Fields are also supported in this Notification:
[hilite mono]%%date_of_birth%%[/hilite] would be valid; if you have a Custom Registration/Profile Field with the ID [hilite mono]date_of_birth[/hilite].
[hilite mono]%%street_address%%[/hilite] would be valid; if you have a Custom Registration/Profile Field with the ID [hilite mono]street_address[/hilite].
[hilite mono]%%country%%[/hilite] would be valid; if you have a Custom Registration/Profile Field with the ID [hilite mono]country[/hilite].
[hilite mono]%%etc, etc...%%[/hilite] see: s2Member -> General Options -> Registration/Profile Fields.