Audit logging (audit reports) are used to view the information in a logging database about user and report activity.
Sample audit report definitions might be:

User calls made from Cognos 8 components

Agent execution history by user

Daily average and poor exceptions

Daily metric exceptions

Execution history reports by package, report, user

Failed service requests detect agent

Logon operations by time stamp, username,

User sessions - abnormal termination, logon errors, etc.

A few sample audit reports are available in the Cognos samples installation package