Content Filtering is a feature in the PSB portal located within the Browsing Protection tab. Content Filtering allows you to block web content based on the file type; for example, .swf, .jar, .exe.
The feature works as a safeguard in conjunction with a Security Cloud look-up of the domain/URL. While the F-Secure Security Cloud has ratings for a vast number of websites, new sites are coming all the time. In case there is no rating for a site yet, this functionality can help protect you by blocking file types according to the Content Type Filtering table in the PSB portal.
In practice, if the Security Cloud deems the domain/URL safe, the download is not blocked. However, if the Security Cloud deems the domain/URL unsafe, access is blocked, regardless of the file types selected in Content Filtering.