Among Internet based brokers and agents the LOI is commonly advanced as a leading inquiry document. This protocol is utterly incorrect, and misuse of the LOI is often seen by experienced Exporters as a mark of an amateur. Letters of Intent are not standard international business documents, though they do legitimately pop up rarely, much less often than most brokers believe.
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.