Prior to 2014, documents could be "unclassified". So there's that.
Sec. 1.4. Classification Categories. Information shall not be considered for classification unless its unauthorized disclosure could reasonably be expected to cause identifiable or describable damage to the national security in accordance with section 1.2 of this order, and it pertains to one or more of the following:
(a) military plans, weapons systems, or operations;
(b) foreign government information;
(c) intelligence activities (including covert action), intelligence sources or methods, or cryptology;
(d) foreign relations or foreign activities of the United States, including confidential sources;
(e) scientific, technological, or economic matters relating to the national security;
(f) United States Government programs for safeguarding nuclear materials or facilities;
(g) vulnerabilities or capabilities of systems, installations, infrastructures, projects, plans, or protection services relating to the national security; or
(h) the development, production, or use of weapons of mass destruction.
https://www.whitehouse.gov/the-press-office/executive-order-classified-national-security-information