The P3 itself contains more than what I commented on.. I was only referring to the items to return [ASAP]... It's now down to just two documents.
Consulate in GUZ, K1 P3 contents:
http://guangzhou.usconsulate.gov/kvfaq.html
What documents will be in the instruction packet and appointment packet?
The Instruction packet in Guangzhou includes:
Instruction packet (Packet 3) letter in English
Instruction packet (Packet 3) letter in Chinese
Application for immigrant visa and alien registration (DS-230 part I)
Instructions for immigrant visa applicants (OF-169)
Notice to all nonimmigrant visa applicants (list of CITIC Bank)
Evidence which may be presented to meet the public charge provisions of the law (OF-167)
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as Yodrak says on Aff. of Support... Your SO should have this for the interview.