FortiProxy
FortiProxy provides enterprise-class protection against internet-borne threats and Advanced Web Content Caching
hrahuman_FTNT
Description This article describes difference between file type and Pattern in DLP.
Scope  
Solution

The file type is to scan the actual content of the file.

The file pattern is to check the name of the file.

 

For Example:

if the zip does not contain the valid archived content then FortiProxy will identify the filetype as 'filetype=unknown' so it will not be blocked.

 

At the same time, the file pattern scans the exact filename with extension (*.zip) so it will get blocked.