"custom_ca_certs" missing from index of inventory variables in Install Guide

Appendix A "inventory variables" of the "RHAAP Installation Guide" does not list the "custom_ca_certs" variable that is mentioned in the example inventories in Chapter 3.1.1.x

I wanted to look up whether it also accepts a list as a parameter, but it's not in the index for AAP 2.3 and 2.4, possibly also even older ones.