Synchronous Versus Asynchronous Calls
If a caller makes a synchronous call, the caller has to wait until the process completes and they receive a response. If a caller makes an asynchronous call, the caller does not have to wait for the processing to complete or receive a response.
Returning Free Products
If a customer returns a bundled product that contains a licensed product that cost x number of dollars and product that is free ($0.00), the whole order is returned (that is, the customer returned all line items including the free items), including digital rights. You should send a Digital Rights Revocation for any product set up with an external dispenser that was dispensed with that dispenser.
You give satisfaction refunds to a customer to make them happy and allow them to continue using the product. You should advise the API consumer to not revoke the digital rights when they receive a Digital Rights Revocation with this reason. Note that the API consumer might want to take other actions (for example, a client might want to cancel auto renewals on a satisfaction refund).