13.7 Shared and Non-Shared Caches
For reasons of security and privacy, it is necessary to make a distinction between "shared" and "non-shared" caches. A non-shared cache is one that is accessible only to a single user. Accessibility in this case SHOULD be enforced by appropriate security mechanisms. All other caches are considered to be "shared." Other sections of
this specification place certain constraints on the operation of shared caches in order to prevent loss of privacy or failure of access controls.