http://www.parks.com/ http://www.usparks.com/ http://parks.thisdomain.com/The same concept goes for a rule in the "Deny" class, except instead of being allowed access to the URL they will be denied access. For example, if the rule was "sex" then they would be denied access to URLs such as:
http://www.sex.com/ http://www.sexygirls.com/ http://sex.fun.com/However, they would also be denied access to sites such as "http://www.middlesex.com/" because the word 'sex' occurs in the URL.
In summary, the best approach is to add "Deny" rules for broad words, and if people start complaining about not being able to access valid sites then add an "Allow" rule for that site. Taking the 'sex' example from above: