answer: #Person2# tells #Person1# the terms should be amplified to express the different methods of payment. They must be very careful in building up clear expressions.
documents: #Person1#: Are the expressions of sight draft, time draft, usance draft and letter of credit adequate terms to express the different methods of payment?
  #Person2#: No. These terms need to be amplified.
  #Person1#: What if the sale is made on the basis of sight draft?
  #Person2#: Then the shipping documents have to be attached. That way, both parties confirm the documents that will accompany the draft and constitute evidence of shipment in compliance with the contract terms.
  #Person1#: Therefore, we must be very careful in building up clear expressions and complete understanding on both sides of trade.
  #Person2#: Yes, that's very important.