Custom URL categories and external dynamic lists of type URL are displayed under Category. By default, Site Access and User Credential Submission permissions for all categories are set to allow. The URL Filtering Profile Allow Categories best practice check ensures the URL categories under the Site Access section are not set to allow. If traffic is set to allow from a URL category, the firewall doesn’t log that traffic. So there will be no visibility into traffic to websites in that UR category. For URL categories that are not blocked, set the Site Access action to alert to log traffic to all websites.