Letters of intent may be advanced in the world of commercial real estate. In some specific domestic markets (for example in principal to principal deals between upstream Petroleum traders and producers in the same country, or certain Joint venture projects) they may be found. But there is no underlying and supported standard international application for the Letter of Intent.
In the majority of cases, a separate NDA (aka confidentiality agreement [CA]) will have been executed between the parties during the initial discussion stage, prior to the drafting of a LOI. An NDA imposes binding obligations of confidentiality that will survive the non_binding letter of intent.