How: affirmation (no impediment to marry) letter, cambodian embassy?

Hi,
I have been reading a few topics but not quite the exact answer. The embassy has been slow to answer.

I (a Canadian) will marry my Cambodian girl in bangkok. I know she needs this letter, and they must stamp it a the embassy. What does she bring to get this affirmation? Divorce letter, widow letter, birth certificate, pass port?

Anything else I dont know?
Much thanks. Its somewhat urgent.

Hmm... maybe an easier question.

Is the "celibacy, widowhood, divorce" letter the same thing? If so I think we already have it. Please confirm anyone?

http://bnglegal.com/cn/wp-content/uploa … mbodia.pdf