NIST SP 800-64 R2 October 2008 Security Considerations in the System Development Life Cycle, has been developed to assist federal government agencies in integrating essential information technology (IT) security steps into their established IT system development life cycle (SDLC). This guideline applies to all federal IT systems other than national security systems. The document is intended as a reference resource rather than as a tutorial and should be used in conjunction with other NIST publications as needed throughout the development of the system.