Chapter 15 Unified Threat Management for FortiOS 5.0 : Data leak prevention : File filter : General configuration steps
  
General configuration steps
The following steps provide an overview of file filter configuration. For best results, follow the procedures in the order given. Also, note that if you perform any additional actions between procedures, your configuration may have different results.
1. Create a file filter list.
2. Create one or more file patterns or file types to populate the file filter list.
3. Enable the file filter list by adding it to a filter in a DLP sensor.
4. Select the DLP sensor in a security policy.