This enables or disables sending TACACS+ accounting records specifically for session logon and logoff events. This is a finer-grained toggle than the overall accounting admin state, letting an admin log session-level access, who logged in or out and when, without necessarily also logging every individual command via the command-accounting object, which produces a much larger volume of records. For example, an admin wanting a lightweight audit trail of who accessed the device and for how long, without the overhead of a full command-by-command log, would enable this object while leaving command accounting off.