In the diplomatic trade screen I find the text for the trade item "Open Borders" a bit unclear and inconsistent. It reads "Allow each other's ships to pass through your respective territories without diplomatic penalty." It appears the text was designed to be used for both sides of the trade, but it shows up only on my side of the trade options (perhaps because the AI I am trading with has not yet researched the appropriate tech) and when I select it as something I want to trade the AI responds with "Your gift will be gladly received."