LOI is fraught with many legal booby traps & pitfalls especially for the buyer. But probably the most damning reason why credible crude buyers would have little or no use for LOI in their buying dealings, is that using the LOI is fraught with many incalculable legal traps and pitfalls much of which could atimes be very costly for, and to the detriment of, the buyer, according to legal authorities and contract law experts.
The second important element is to clearly state the intended parties outcome from the disclosure. In the example above the intended outcome could be "The information is being disclosed to assess whether XYZ transportation company will pilot the software for use within its fleet". Again it is then clear what the outcome and the nature of the relationship will be. The example above is broad enough to allow some flexibility in discussion in the letter of intent e.g. that perhaps the pilot programme is limited to one territory as negotiations progress, but it must be narrow enough that the outcome is reasonably well known e.g. it is not expected that XYZ transportation become a shareholder in the software company.