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.
The point is that the often_heard notion and claims by some sellers or their overzealous agents and brokers that the use of the LOI to initiate a purchasing proposal by a buyer "is how it is usually done and this is how it should be," may be applicable and prudent only in the minds, the imagination, and hopes or dreams of those sellers, especially the more marginal ones and their brokers and agents who operate on the fringes largely on the Internet. It is NOT a view that is shared by the broad spectrum of credible buyers, more especially when the "sellers" involved are largely unknown and obscure operators.