 During the reign of Prince-Bishop Petar I Petrović-Njegoš, a special document known as "Passport" () was granted to the citizens who wanted extraordinarily to visit foreign countries.During the reign of Prince-Bishop Petar II Petrović-Njegoš, he was granting a special Montenegrin Bill of Passage.From then on, next to every user of the bill and subsequent passports, "Montenegrin" was added, relating to the country of his or her birth.