My experience comes mostly from the U.S. Army. When officers are commissioned, they get a Secret Clearance as the base level for what material they can see. Confidential information in the Army, at the unit level, had to do with military readiness reports for individual battalions and also the code books used for sending coded radio messages. Most of all that is now done electronically.
Here’s a good primer for you: “List of U.S. security clearance terms.” I’ll highlight some sections below:
“Security clearances can be issued by many United States of America government agencies, including the Department of Defense (DoD), the Department of State (DOS), the Department of Homeland Security (DHS), the Department of Energy (DoE), the Department of Justice (DoJ), the National Security Agency (NSA), and the Central Intelligence Agency (CIA). DoD issues more than 80% of all clearances. There are three levels of DoD security clearances:[1]
- TOP SECRET – Will be applied to information in which the unauthorized disclosure could reasonably be expected to cause exceptionally grave damage to the national security. This level of clearance is generally reserved for the President of the United States, United States Secretary of State, U.S. Speaker of the House, United States Secretary of Defense, United States Secretary of the Treasury, U.S. National Security Advisor, United States Attorney General, Director of the CIA, and a limited other United States government personnel.
- SECRET – Will be applied to information in which the unauthorized disclosure could reasonably be expected to cause serious damage to the national security.
- CONFIDENTIAL – Will be applied to information in which the unauthorized disclosure could reasonably be expected to cause damage to the national security.
- USAP: Unacknowledged SAP & "Waived USAP" - Made known only to authorized persons, including members of the appropriate committees of the US Congress. Waived USAP is a subset of USAP.
- ACCM: Alternative or Compensatory Control Measures - Security measures used to safeguard classified intelligence or operations and support information when normal measures are insufficient to achieve
strict need-to-know controls and where SAP controls are not required”
My highest level of clearance was Top Secret/SCI, which is explained below:
The reason I had a TS/SCI clearance was that I worked on a Code Word project that had to do with the continuity of government (COG) for our national command authorities. Later, in another assignment, because I had a Top Secret clearance I was part of a team of officers who could decode nuclear attack orders that were being sent to military units. This was years ago, but I’d have to go down to the SCIF, a sensitive compartmented information facility (SCIF; pronounced /skɪf/) to practice decoding messages to maintain my proficiency.
At one point in my career I had responsibility for the security of a SCIF. It is not just a simple safe or file safe. In my case it was a large concrete room built within a room that had a very heavy bank vault type door with a safe combination lock. Only someone with a TS/SCI clearance could enter it. The facility was used for the transmission of highly classified communications and the storage of Top Secret information. TS information cannot be just kept in a storage room with a padlock door.
People who have a TS/SCI clearance must undergo a Single Scope Background Investigation, a type of United States security clearance investigation. It involves investigators or agents interviewing past employers, coworkers and other individuals associated with the subject of the SSBI. It is governed by the U.S. Intelligence Community Policy Guidance Number 704.1. Standard elements include background checks of employment, education, organization affiliations and any local agency where the subject has lived, worked, traveled or attended school. These checks lead to interviews with persons who know the subject both personally and professionally. The investigation may include a National Agency Check with Local Agency Check and Credit Check (NACLC) of the subject’s spouse or cohabitant.
In my case, I recall a next door neighbor telling me he was visited by a federal agent inquiring as to my conduct, habits, etc., in and around the place where we lived. It is not just a simple records check.
Hopefully the above makes you a more informed consumer of national news.