On Fri, Mar 28, 2014 at 12:25 PM, Andreas Schildbach <andreas@schildbach.de> wrote:

I see the problem.

However, I don't see how PaymentDetails can be an answer. None of the
fields (other than outputs and network) can be known in advance (at the
time of the initial payment).

You're probably aiming for an expires field? How would you refund a
payment after expiry? Note its not your choice wether to refund a
payment -- it can be ordered by a court years after the payment happened.

Communication between the merchant and buyer would be needed in this case.

I'd say that would be not unreasonable if something is to be refunded after a year or more. After all, people may have moved, bank accounts changed, even outside the bitcoin world.

It should probably not be accepted to set a very low expiration time for the refund address, like <3 months, as it's as bad as not providing a refund address at all and brings back all the pre-BIP70 confusion.

Wladimir