When I order the books to Europe (The Netherlands) it is not clear where it will come from. If it will come from USA (printed and sent from US), then I will need to pay customs taxes if price is more then 22 Euro, if It will come from European Union (printed and sent from EU), then I will not need to pay customs taxes. Many people does not know this and can get unexpected custom taxes. Also for people who knows about this, it will be good indication, because in my case I had to create a support request in order to get this information.
To avoid this issue it will be good to indicate it clearly during the order placing, maybe on final confirmation page put a text "Your books will be printed and sent from Country A, please check you local customs tax rules for delivery from this Country A" and after order is placed in the order page display the same information "Books printed in: Country A", "Books sent from: Country A".