= O =
Orange Book n.
The U.S. Government's (now obsolete)
standards document "Trusted Computer System Evaluation
Criteria, DOD standard 5200.28-STD, December, 1985" which
characterize secure computing architectures and defines levels A1
(most secure) through D (least). Modern Unixes are roughly C2.
See also crayola books, book titles.
--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.