This work was created by or on behalf of either the government, the former national Fascist Party, an academy, or a non-profit organisation of Italy. It was published prior to 1976, and has no known US copyright registration associated with it. It is now in the public domain in Italy and the United States and possibly elsewhere because its copyright term has expired.
According to Law for the Protection of Copyright and Neighbouring Rights n.633, 22 April 1941, revised by the law of 6 February 2016, copyright in works created and published under the name and at the expense of national, provincial and communal governments shall belong to the relevant administration; the same right shall also belong to private legal entities of a non-profit-making character, as well as to the academies and other public cultural organisations (Art. 11). The duration of the rights belonging to the government, the former national Fascist Party, academies and non-profit or public cultural organisations shall be twenty years from first publication, whatever the form in which publication was affected (Art. 29).
This may not apply in countries that don't apply the rule of the shorter term to works from Italy. In particular, these are in the public domain in the United States only if:
wasn't in copyright in the United States due to being registered for copyright there (see Commons:Copyright tags#United States for most cases) and
was created prior to 1976 and published prior to 1978 — then it was out-of-copyright in Italy on the URAA date of restoration (January 1, 1996) (17 U.S.C.§ 104A) (in most cases; for all cases, see Template:PD-Italy/US). If so, please add {{PD-1996}} in addition to this copyright tag. If the image was created on 1976 or later, please add {{Not-PD-US-URAA}}.
This file shows or is part of a text of official act published and distributed by the Italian State or Italian public administration. According to Italian copyright law, this work is in the public domain in Italy unless the copyright has been reserved explicitly. §5 of Italian copyright law specifies that no copyright exists in such material: "The provisions of this Law shall not apply to the texts of official acts of the State or of public administrations, whether Italian or foreign."
This work is in the public domain in the U.S. because it is an edict of a government, local or foreign. See § 313.6(C)(2) of the Compendium of U.S. Copyright Office Practices, 3rd ed. 2014 (Compendium (Third)). Such documents include "legislative enactments, judicial decisions, administrative rulings, public ordinances, or similar types of official legal materials."
These do not include works first published by the United Nations or any of its specialized agencies, or by the Organization of American States. See Compendium (Third) § 313.6(C)(2) and 17 U.S.C. § 104(b)(5).
A non-American governmental edict may still be copyrighted outside the U.S. Similarly, the above U.S. Copyright Office Practice does not prevent U.S. states or localities from holding copyright abroad, depending on foreign copyright laws and regulations.