Traders are better off NOT using documents like LOI, ICPO, FCO, etc. Even if and when they rarely are used in internal trades, on a restricted level within specific industries, they have no legal or customary basis in International Trade whatsoever. In fact the presence of many of these terms are considered to be signs of Advance Fee Fraud, by knowledgeable players and law enforcement.
"Letters of intent are often touted as a 'non_legally binding' way to get the parties to set forth in writing what the undertaking is among them relative to a transaction. Too often, parties will sign such a document, feeling that they have little or nothing to lose by doing so... [True, that's] one of the attractive elements of the letter of intent [its purported non_binding nature]. However, courts have found letters of intent to create binding obligations, even if the letter itself does not explicitly state that it is binding... certain provisions within the document may indeed [still] have legal effect."