If this policy is enabled, and the website filter is enabled, you can specify match patterns for sites you do not want to block. The match patterns are documented at https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Match_patterns. Only http/https addresses are supported at the moment. There is a 1000 entry limit.
If this policy is disabled or not configured, there are no exceptions to the website filter.
|Registry Hive||HKEY_LOCAL_MACHINE or HKEY_CURRENT_USER|