Chapter 13 Logging and Reporting : Advanced logging : Customizing FortiOS reports with CLI
  
Customizing FortiOS reports with CLI
You may want to configure a FortiOS report to create a specific report that contains only specific charts and images. A FortiOS report is created in the CLI. A FortiOS report is time-consuming, so allow plenty of time for creating this type of report.
Reports are made up of four components:
Charts, which are the content of the report
Datasets, which determine what information is contained in the charts
Styles, which determine the appearance (text style, etc) of the content
and Themes, which determine the structure of the report
You should also review the FortiGate CLI Reference since it contains detailed information about each command used in the following.