Organizations such as the Federation, Starfleet, and Starfleet Intelligence use different levels of access to secure and control information. While Starfleet provides officers and enlisted personnel free access to most of its vast library database, it recognizes that certain types of information must be kept confidential to ensure the safety of the Federation. Information regarding weapon and shield frequencies, tactical and strategic procedures and plans, and technology development programs are typically kept under wraps to prevent the enemy from gaining access and obtaining an advantage over the Federation.

Access to certain areas and equipment aboard a Starship is restricted to certain authorized personnel. To facilitate this security concern, numerical levels are assigned to crew or visitors as necessary.

Note: Security Levels beyond current rank can and are bestowed where, when and to whom they are necessary.

The main computer grants access based on a battery of checks to the individual user, including face and voice recognition in conjunction with a vocal code as an added level of security.

Starfleet and Starfleet Intelligence use four primary levels of security classification, detailed in the following sections:

Information at this security level isn't secure at all; it's freely available to anyone who can use an LCARS terminal or similar data retrieval system. By some estimates, as much as 98% of Starfleet's information fits this category. Examples include most economic and scientific data, routine reports prepared by Federation agencies and offices, and recordings of most Federation Council proceedings. OA information is not always as innocent as it seems. A clever intelligence agent or data analyst can piece together random bits of OA data to uncover leads on Federation secrets. For example, scientific reports may contain hints on recent Starship locations, which might reveal a clue regarding their mission objectives or Starfleet's deployment strategy in a region.

Rank routinely receiving access to this clearance level: All personnel, Civilian or otherwise

Secret information would cause harm to Starfleet or the Federation if released to unauthorized persons. Examples include most information relating to fleet, Starship strengths, war games results, and precise weapons characteristics.

Rank routinely receiving access to this clearance level: Lieutenant Junior Grade and above

Top Secret information would cause significant harm to Starfleet or the Federation if released to unapproved personnel. If obtained by a Threat species, it could compromise Federation security. Key scientific data relating to military research and development projects (such as Starship propulsion and weapons systems) and Starfleet's overall strategic plans for defending the Federation are all consideredTop Secret.

Rank routinely receiving access to this clearance level: Lieutenant and above

Ultra Secret information, also called omega-class information, could cause extreme harm to Starfleet or the Federation if released. If obtained by a Threat species, it could significantly compromise Federation security or Starfleet's ability to defend itself. In some cases, the mere revelation of Ultra Secret information can be enough to spark war or ruin relations between the Federation and other governments. Examples include details of the most sensitive espionage operations conducted by Starfleet Intelligence, keys to Starfleet codes and ciphers, and critical scientific and technological data.

Rank routinely receiving access to this clearance level: Commander and above

Several secondary classifications further restrict, limit, or guide the dissemination of Federation data files: (These generally appear as suffixes to the Clearance Level. For instance, a document could be labeled OMEGA-SSI or SECRET-CWD)

Information with this designation, which is usually Secret or Top Secret, is authorized for limited release to members of the Federation Council. Councilors are, of course, aware that they are not to distribute or disseminate this information in any way, not even to their closest staff members.

Rank routinely receiving access to this clearance level: Admiral's and Councilors Only

Usually applied to Top Secret or Ultra Secret information, CWD indicates the data relates to the characteristics, limitations, and advancement of Starfleet's weapons. Since such data is vitally important to Starfleet's ability to defend the Federation, it receives this extra classification and a more intense level of scrutiny. Communications Security Information (CSI) is a similar designation which applies to data on Starfleet's communications capabilities and crypto logical resources.

Rank routinely receiving access to this clearance level: Lieutenant Commander and above

Usually applied to Top Secret or Ultra Secret information, CWD indicates the data relates to the characteristics, limitations, and advancement of Starfleet's weapons. Since such data is vitally important to Starfleet's ability to defend the Federation, it receives this extra classification and a more intense level of scrutiny. Communications Security Information (CSI) is a similar designation which applies to data on Starfleet's communications capabilities and crypto logical resources.

Rank routinely receiving access to this clearance level: Lieutenant Commander and above

Usually applied to Top Secret or Ultra Secret information, CSI indicates the data relates to the Communications Intelligence, Crypto logical Intelligence, Sensors Intelligence, or Signals Intelligence of a sensitive nature which may reveal its sources.. Since such data is vitally important to Starfleet's ability to defend the Federation, it receives this extra classification and a more intense level of scrutiny.

Rank routinely receiving access to this clearance level: Lieutenant Commander and above

Sometimes intelligence reports and similar data must, by their nature, reveal their sensitive sources. Revealing contact and informant names might expose them to the enemy. Likewise, information that reveals the capabilities of Starfleet's sensors and analytical technology could provide invaluable data to a Threat species. This classification indicates that the file in question reveals facts about its sources and must be treated with the greatest caution.

Rank routinely receiving access to this clearance level: Captain and above