All rules created from WFC have by default the group "Windows Firewall Control". This is already a predefined authorized group which can't be removed. So, if you enable Secure rules feature, all rules created by you from WFC will be anyway in this authorized group. You can have tens of authorized group names, so you don't have to use a single group name for all of your rules. In Rules Panel, when you filter the rules to see "User defined rules", this is referring to the rules which have the group "Windows Firewall Control". If you have a custom group name, let's say "Authorized rules" and you want to filter the rules to see only these you can use the search text box to input "aut" and you will see only the rules from this custom group.