In the history sidebar (the clock) on ServiceNow, Incidents, lists, and some other record types print the title or some other meaningful information. REQs (and some other record types) just showthe record number.
This history shows different for different record.
Items you have accessed recently appear in the history tab of the application navigator, which is represented by a clock icon.
Items appear in chronological order from most to least recently accessed.
History entries are stored on the Navigator History [sys_ui_navigator_history] table. The system creates history entries for many types of content, including lists, records, and homepages. Some content types are not tracked in the history, such as UI pages and other non-standard interfaces.
These history are created by system hence can't be customizable.