o. "In-App Product" means a supplementary digital item for an App that is offered for purchase in the Store, whether on a fixed or recurring basis; after an In-App Product is purchased by a Customer, it is delivered to the App by the developer.
e. In-App Commerce. You may elect to make In-App Product(s) available for purchase from within your App. Beginning June 29, 2015, new App and In-App Product submissions to the Store are required to use Microsoft's commerce engine to support purchase of In-App Product(s) that are consumed or used within an App. Apps that are publicly available in the Store before June 29, 2015 may offer functionality to purchase In-App Product(s) that do not use Microsoft's commerce engine so long as the purchase functionality complies with the Certification Requirements. Beginning June 29, 2016, all Apps must use Microsoft's commerce engine to support purchase of In-App Product(s) that are consumed or used within an App. Any in-app purchase functionality that you offer for purchase of any product or service not consumed or used within your App must comply with the Certification Requirements. All purchases using Microsoft's commerce engine will be subject to the terms of this Agreement, including without limitation the Store Fee, Application Requirements (including the Certification Requirements for In-App Product), and licensing requirements. If your App allows any purchasing from within the App you must prominently disclose in your product description that In-App Purchase functionality is available. If your App uses a non-Microsoft commerce engine, you must disclose that information in the product description.