The ISO 15408 IT Security Techniques - Evaluation Criteria for IT Security, so-called "Common Criteria":
The Common Criteria comprises three parts:
1. Security General Model
2. Security Function Components
3. Security Assurance Components
Please have a look to our brandnew Common Criteria Quick Reference Card g that provides a fast overview and access to the standardized definitions and guidelines around Security Functional Requirements (SFR) and Security Assurance Requirements (SAR).