What subscriber information can be collected by developers when implementing iOS subscriptions?

Question

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:

1. Are subscriber name, e-mail and zipcode the only pieces of information available via iTunes Connect?

2. If (1), is this information available only through opt-in?

3. If (1) and (2), how does the opt-in process work?

Answer 1

1. I think so. Although I've never received this info, based on the dialog below, I can only assume you don't get more info than they list.
2. Yes. You can't require the information. You'll only get the information if the user opts in.
3. You don't have to request that the user be prompted. In fact, you can't prevent the dialog from appearing when the user first subscribes to your auto-renewing subscription.

From Marco Arment's post on The limited world of auto-renewable subscriptions:

There’s no way for a developer to opt out of this data collection and disable this dialog. If you sell an auto-renewable subscription, your customers will be told that you want their personal information, and you will be given that information [...] whether you wanted it or not.

Please read the rest of his post to see why you may want to steer away from ARS. Apple may reject your app if you're not a magazine or newspaper.

This is what the dialog looks like: