A translation of treaties between the Vatican and Italy on the internet holds some clues to the inviolability of Vatican-owned real estate in Italy, papal documents located or in transit in Italy and the special status of diplomats accredited, and staff employed, by the Vatican but operating outside Vatican City.
The embassy-law issues of immunity and inviolability become important in the relations between Italy and the Vatican. According the various reports, Italy gained possession of documents prepared for the Vatican head of state, Pope Benedict XIV, in the search of a dismissed Vatican executive's house in Italy by Italian officials.
The two nations are reportedly embroiled in a conflict over the seizure. The Conciliation Treaty, one of the Lateran Pacts of 1929, offers solutions in several articles beginning with Article X. -- Clemens Kochinke, partner, Berliner, Corcoran & Rowe, LLP, Washington, DC.