The type of environment in which the checklist is intended to be applied. Types of operational environments are Standalone, Managed, and Custom (including Specialized Security-Limited Functionality, Legacy, and United States Government).
Sources:
NIST SP 800-70 Rev. 4
under Operational Environment
Context determining the setting and circumstance of all influences on a delivered system.
Sources:
NIST SP 800-160v1r1