Public Domain means information that is published and that is generally accessible or available to the public through:
(1) sales at newsstands and bookstores;
(2) subscriptions available to any individual who desires to obtain or purchase the published information;
(3) libraries open to the public or from which the public can obtain documents;
(4) patents available at any patent office;
(5) unlimited distribution at a conference, meeting, seminar, trade show or exhibition, generally accessible to the public, in the United States; please make sure you review the definition of Deemed Exports in this situation.
(6) public release (i.e., unlimited distribution) in any form (e.g., not necessarily in published form) after approval by the cognizant U.S. government department or agency; and
(7) fundamental research.
22 CFR 120.11