44.6.2. Security Levels, Objects and Subjects
As discussed above, subjects and objects are labeled with
Security Levels (
SLs), which are composed of two types of entities:
Examples of
SLs are: { Secret / UFO, Crypto }, { Top Secret / UFO, Crypto, Stargate } and { Unclassified }
Note the hierarchical sensitivity followed by zero or more categories. The reason for having categories as well as sensitivities is so that sensitivities can be further compartmentalized on a need-to-know basis. For example, while a process may be cleared to the "Secret" sensitivity level, it may not need any type of access to the project "Warp Drive" (which could be the name of a category).
Note
Security Levels on objects are called Classifications.
Security Levels on subjects are called Clearances.
Thus, objects are labeled with a Classification, while subjects operate with a specific Clearance. Security Levels can have also Ranges, but these are beyond the scope of this introduction.