Mozilla Firefox: 2.3 to 2.11

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. [removed: 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.

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. [removed: 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.

If this policy is enabled, you can specify a URL to be used as the first run page. If you leave the URL blank, no first run page will be shown. [added: Starting with Firefox 83, Firefox ESR 78.5, you can also specify multiple URLS separated by a vertical bar (|). ]If this policy is disabled or not configured, the first run page is displayed.