Atomic Energy Act of 1954, Chapter 2, Section 11(y). https://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr0980/ml022200075-vol1.pdf#pagemode=bookmarks&page=14
Alex Wellerstein (2021). Restricted data: The history of nuclear secrecy in the United States. Chicago: University of Chicago Press. ISBN 978-0-226-02038-9., 145–158. 978-0-226-02038-9
Atomic Energy Act of 1954, Chapter 2, Section 11(y). https://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr0980/ml022200075-vol1.pdf#pagemode=bookmarks&page=14
This interpretation does not seem to have been foreseen by the creators of the concept, however. See Alex Wellerstein (2021). Restricted data: The history of nuclear secrecy in the United States. Chicago: University of Chicago Press. ISBN 978-0-226-02038-9., page 455, footnote 70. 978-0-226-02038-9
See 'United States v. The Progressive (1979). /wiki/United_States_v._The_Progressive
Alexander De Volpi; Jerry Marsh; Ted Postol & George Stanford (1981). Born secret: the H-bomb, the Progressive case and national security. New York: Pergamon Press. ISBN 0-08-025995-2. 0-08-025995-2
U.S. Department of Energy, "An Overview of the Restricted Data and Formerly Restricted Data Classification System" https://www.osti.gov/opennet/forms.jsp?formurl=od/rdfrdhtm.html#I4