A category is a collection of URLs, domains, phrases, lists of file types, security rules, or any combination of these. When you buy your Smoothwall Filter, it comes with built-in categories to which you can add and remove content but you can't delete the categories themselves. However, you can add your own custom categories, which you can delete.
The Custom blocked content and Custom allowed content categories are located in the custom categories folder and are built-in categories provided to you when you bought the Smoothwall Filter. You can either quickly add website URLs to these categories using the Quick block or allow function, see our help topic, Blocking or allowing a URL or domain instantly, or you can manage the URLs in the categories on the policy objects Categories Page page by editing the category within the Custom Categories folder, see the follow-up task on how to edit a category within our help topic Creating custom categories. These two categories are used in the default policy table to block and allow websites for the "Everyone" group and you can't delete them.
The Standard Categories folder contains lots of built-in categories provided when you bought your Smoothwall Filter. These built-in categories contain lists of millions of websites that we update daily. These categories also contain our dynamic content analysis rules to categorize sites not already categorized. You can add your own sites to our built-in categories on the policy objects Categories Page page by editing the category within the Standard Categories folder, see the follow-up task on how to edit a category within our help topic Creating custom categories.
Note: You can't delete any built-in categories provided when you purchased your Smoothwall Filter.