Fortinet 5.0 Patch 6 - page 547

Fortinet 547 FortiWeb 5.0 Patch 6 Administration Guide
2. Configure these settings:
Setting name Description
Enable Attack Log Enable to log violations of attack policies, such as server information
disclosure and attack signature matches, if that feature is configured
such that Action is set to Alert, Alert & Deny, or Alert & Erase.
Enable Traffic Log Enable to log traffic events such as HTTP requests and responses,
and the expiration of HTTP sessions.
Tip: Because resources for this feature increase as your traffic
increases, if you do not need traffic data, disable this feature to
improve performance.