(1) An indicator that appears in the current program status word whenever an associated task has control of the system. This indicator must match the storage keys of all main storage blocks that the task is to use.
(2) A hardware key associated with each page of virtual memory that is available in POWER6 processors and is supported as of AIX Version 5.3 with the 5300-06 Technology Level. Access to pages is controlled on a per-thread basis depending on the access mode of the running thread as represented in the authority mask register (AMR). See also authority mask register.