Hi Pjiang,
關於白皮書 (Reentry permit) application for my PR parents: there are options of letting the approval letter to be sent to China in Guangzhou, or be sent to US address, I chose the US address. I wonder if my parents need to be present (or go to INS office) to get the approval, or they can go to China after the finger print before the approval letter arrives.
Thanks a lot!