URLFilterService works applying filtering rules to combinations of "User groups" per "Categories or mime types". To create a new group just assign it a name(1), permission granted on whitelisted sites(2), permission granted on logs(3), and menu access list(4).
Please note that:
- you don't have the need for multiple user groups when you're the only one using your computer;
- every change you make on a group does not affect users already inserted into the group itself.
"Mime types" are web pages content-type identifiers. They don't have a menu to insert, edit and delete entries. The setup file comes with an archive of types. The archive doesn't include a complete list of all types available, but it gets updated every time an unknown type gets hit in a web page.
"Categories" are computer folders so, when you create new ones, give them a name(2) avoiding special characters like ? < > | * : ". Please note that you can't delete categories and you can't remove sites from a categories if they are coming from the external service.
To create a filtering rule just set the combination you want. Select group(2) and category(3) (or mime type) to add a rule. Select "[EVERYONE]" in user groups to create rules valid for all users/ips.