What is the role of the casebook feature in Cisco Threat Response?

The casebook and pivot menu are widgets available in Cisco Threat Response. Casebook - It is used to record, organize, and share sets of observables of interest primarily during an investigation and threat analysis. You can use a casebook to get the current verdicts or dispositions on the observables.

https://www.cisco.com/c/en/us/td/docs/security/ces/user_guide/esa_user_guide_13-5-1/b_ESA_Admin_Guide_ces_13-5-1/b_ESA_Admin_Guide_13-0_chapter_0110001.pdf