Additions, clarifications, and corrections regarding the content
of this document will be most graciously accepted: please send
email to firstname.lastname@example.org. Rating: Value judgments
are used to categorize web sites based on their content. These
ratings could use simple allowed/disallowed distinctions like
those found in programs like CyberSitter or NetNanny, or they
can have many values, as seen in ratings systems based on
Platform for Internet Content Selection (PICS, see question
3.0). Filtering: With each request for information, the
filtering software examines the resource that the user has
requested. If the resource is on the "not allowed" list, or if
it does not have the proper PICS rating, the filtering software
tells the user that access has been denied and the browser does
not display the contents of the web site. The first content
filters were stand-alone systems consisting of mechanisms for
determining which sites should be blocked, along with software
to do the filtering, all provided b