Not sure how I missed this one, but we need another man page. Note that the iab text format is what is used for the pam_cap.so module config file. Also note that the iab mechanism is used by cap_launch - that is cross-link.
Fixed with https://git.kernel.org/pub/scm/libs/libcap/libcap.git/commit/?id=9ff645410782f7f54d706e8e80f69d4b11857efe