Web filter content list

Hello,

I 've 5.4 fortigate version, my question is: how to set threshold value for content filter? When I read this: http://help.fortinet.com/fos50hlp/54/Content/FortiOS/fortigate-security-profiles-54/Web_Filter/Web%20content%20filter.htm You find how to set "score" for single entry, but there's no clue on how to modify default threshold value for a site... At the end I think that is not possible at all...  Can some help clarify this? Thanks!