CUI information types processed, stored, or transmitted by the system are determined and documented. For more information, see the CUI Registry at https://www.archives.gov/cui/registry/category-list

Focuses on Controlled Unclassified Information (CUI).  It defines CUI, its importance to federal agencies, and the need for its protection within nonfederal systems.  This section clarifies that the document's security requirements apply to any system component that processes, stores, or transmits CUI.  Essentially, it sets the stage for the rest of the document by outlining the core purpose and scope of the security guidelines.

In environments that utilize enclaves, this section will be completed within  Section 0.2.04. Otherwise the entire environment is an enclave.