My app implements the iOS auto-renewing subscription to access premium content. I haven't yet submitted this for approval, because I want to know what subscriber information I'll be able to access once users purchase subscriptions. I need this information so that iOS app subscriptions integrate with a separate business database handling subscriptions on other platforms.
My reading of the typically-cryptic Apple docs is that name, e-mail and zipcode are available but only if the user explicitly opts in. But I'm not clear how to request that this information be asked for during the purchase process, or whether there's additional information I can ask for.
So here are my questions:
Are subscriber name, e-mail and zipcode the only pieces of information available via iTunes Connect?
If (1), is this information available only through opt-in?
If (1) and (2), how does the opt-in process work?