Use Categorize websites to Manage Web-Site Categorization.
Review and modify the categorization of any website.
You can also create new categories, and associate web-sites with those categories.
To Modify a web-site's categorization, you must first use the search box to view its existing categorization.
It will show you the details of Total Number of Categories, Last updated and last changed.
Go to configure page
Go to Custom Settings : Categorize Web-sites
Here you can edit or modify the previously existed category of any website.
Search for category
Here you can find the category of any website in which it is categorized.
Enter the website/domain name in the search box and click on the search button, dialog box of Categories will appear below. In this dialog box you will get a category list(comma separated) in which it is categorized.
Add your website to the custom category
Upload websites file
Here you can upload a file, which should contain the list of websites and add the category to that websites.
Example : search for yahoo.com
It will display: news, portals, search engines
Make one text file with list of websites and Upload that file and add the category, then check the website from that file by search its category, it shows the category added by you.