2.5.1.6. Section 6: Other System Attributes. Optional for an IS-CDD with the exception of consideration should be given to identify the system categorization for information systems and PIT systems as a required capability - the potential impact (low, moderate, or high) resulting from loss of confidentiality, integrity, and availability, if a security breach occurs IAW Reference [10].

For reference or comparison, below is what the JCIDS Manual says for the CDD 2021 itself:

2.5.6.2.3. Human Systems Integration (HSI) considerations that have a major impact on system effectiveness, suitability, and survivability. The HSI Force Protection and Survivability domain contributes to the Force Protection KPP by defining requirements for personnel force protection and personnel survivability. The HSI Safety and Occupational Health domain contributes to the Force Protection KPP by defining requirements for personnel and system safety. DOTmLPF-P analyses should identify and address HSI.