TCSEC (Orange Book) Divisions

 From Wikipedia - Orange book: 

Document	Title	Date	Color
5200.28-STD	DoD Trusted Computer System Evaluation Criteria	August 15, 1983	Orange

Divisions and classes are defined as the following: 

• 2.1D – Minimal protection
• 2.2C – Discretionary protection
• 2.3B – Mandatory protection
• 2.4A – Verified protection
  
  

NOTE: A (verified) has the highest security!