The control catalog behind FedRAMP and federal systems.
Special Publication 800-53 Revision 5 is a catalog of over 1,000 security and privacy controls organized in 20 families. Federal systems select a baseline (low, moderate, high) under FISMA. It is also the reference behind FedRAMP, CMMC, and many state and commercial programs.
These controls exist because the platform needs them to run safely. The crosswalk reads their signed evidence against NIST SP 800-53. Where there is no evidence, the report says gap.