If this policy is enabled, you can specify match patterns that indicate sites to be blocked. 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, no websites are blocked.
|Registry Hive||HKEY_LOCAL_MACHINE or HKEY_CURRENT_USER|