The functionality of the in-app purchase feature is somewhat different depending on whether or not you are protecting the purchasable content with built-in DRM.
With built-in DRM protected content, all the content needed to enable premium (purchasable) functionality is stored in the original application, which the user downloads from Nokia Store. Nokia Store also handles the restoration history and end users' eligibility for restoration, the application just calls the client restoration API.
The category of 'no built-in DRM protection used' is much broader: it includes content to be downloaded from your back end server, content already stored in the application but not protected with DRM, or premium services that do not require any downloadable content. In this case, your back end server delivers content, manages access rights, and should also store information about users' past transactions to enable restoration of purchased content.
Later in this document, content that falls into the category of 'no built-in DRM protection used' is referred to as 'non DRM protected'. This does not imply that the publisher cannot protect the content using some other means.
The following processes describe the options for how purchasing and restoration are done. There are some differences in the process depending on whether or not the content is DRM protected.
For more information about purchase and restoration, see: