About category groups
A category group is a collection of categories, made up of URLs, domains, phrases, lists of file types, security rules, or any combination of these. The Smoothwall Filter uses these groups in web filter policies to determine if a user should be allowed access to the content that they have requested using their web browser.
If you're using a multitenant configuration, you can't change the tenant assigned to a category group, as that group might form part of a tenant-specific policy.
You can't delete a category group object if it's in use in a policy. You must first remove the object from the policy.