In the early stages there's various options available to you. It is extremely important that you choose the most suitable style so your document presents as professional as possible. You can select from varying styles including Block Style, Modified Block Style, Semiblock Style. You can have a look at these varying options and select the one that you consider is most suitable.
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.