From MozillaZine Knowledge Base
Since Firefox 1.0, the â€œPlugin Finder Serviceâ€ has been available to locate missing plugins for web content. To accomplish this, Firefox sends the MIME type of the embedded content along with some information about the browser to a URL on Mozillaâ€™s web servers. Details for downloading the necessary plugin are returned, and Firefox can then present the user with the option to install it.
The URL used to retrieve plugin information is determined by this preference.
Possible values and their effects
The URL to use for retrieving RDF-based data on plugins for web content. Default value is https://pfs.mozilla.org/plugins/PluginFinderService.php?mimetype=%PLUGIN_MIMETYPE%&appID=%APP_ID%&appVersion=%APP_VERSION%&clientOS=%CLIENT_OS%&chromeLocale=%CHROME_LOCALE%&appRelease=%APP_RELEASE%, where
First checked in
Has an effect in