Protected Critical Infrastructure Information (PCII)
PCII is [information and communications] protected from disclosure. All critical infrastructure information that has been properly submitted and validated pursuant to the Critical Infrastructure Information Act and implementing directive; all information submitted to the PCII Program Office or designee with an express statement is presumed to be PCII until the PCII Program Office determines otherwise. Critical infrastructure information voluntarily shared with the government and validated as PCII by the Department of Homeland Security is protected from, the Freedom of Information Act (FOIA), State, local, tribal, and territorial disclosure laws, use in regulatory actions and use in civil litigation. PCII can only be accessed in accordance with strict safeguarding and handling requirements, and only trained and certified federal, state, and local government employees or contractors may access PCII. (CII Act of 2002, 6 U.S.C. § 131, and www.dhs.gov/pcii-program).
U.S. Election Systems as Critical Infrastructure, U.S. Election Assistance Commission, https://www.eac.gov/assets/1/6/starting_point_us_election_systems_as_Critical_Infrastructure.pdf