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:

2.5.6.1. The purpose of this Section is to identify any other system attributes not directly quantified (as performance attributes) and traceable to operational performance, and not identified elsewhere in the document.