В общем тут чел пишет

We are interested in purchasing the XXXXXXXXXXXXX and I would like to know if you are the Sole Source of this product. If so can you please provide me with a Sole Source letter before we make our purchase?

Я ему сказал, что в принципе source code продаем и т.п., но видимо Sole Source это нечто другое, т.к. в ответ он пишет

I wanted to know if you are the only company that we can purchase this software from. That is what I mean by Sole Source, that you are the only company that has this software. We are providing this software to the government and they require this information before we can make a purchase.

Чего ему надо, что-то я недогоняю.