Explanation
https://www.cisco.com/c/en/us/td/docs/security/ise/2-3/admin_guide/b_ise_admin_guide_23/b_ise_admin_guide

Basic certificate checking does not require an identity source. If you want binary comparison checking for the certificates, you must select an identity source. If you select Active Directory as an identity source, subject and common name and subject alternative name (all values) can be used to look up a user.
https://www.cisco.com/c/en/us/td/docs/security/ise/1-
3/admin_guide/b_ise_admin_guide_13/b_ise_admin_guide_sample_chapter_01110.html

Explanation
https://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/Borderless_Networks/Unified_Access/BYOD_Desig The Blacklist identity group is system generated and maintained by ISE to prevent access to lost or stolen devices. In this design guide, two authorization profiles are used to enforce the permissions for wireless and wired devices within the Blacklist:
* Blackhole WiFi Access
* Blackhole Wired Access

Explanation
https://www.oreilly.com/library/view/cisco-ise-for/9780133103632/ch16.html#:~:text=What%20is%20a%2
&text=The%20802.1X%20transactions%20are,Identity%20Services%20Engine%20(ISE).