This policy setting lets you add up to 5 additional search engines, which can't be removed by your employees, but can be made a personal default engine. This setting doesn't set the default search engine. For that, you must use the "Set default search engine" setting.

Important
This setting can only be used with domain-joined or MDM-enrolled devices. For more info, see the Microsoft browser extension policy (aka.ms/browserpolicy).

If you enable this setting, you can add up to 5 additional search engines. For each additional engine, you must also add a link to your OpenSearch XML file, including at least the short name and https: URL of the search engine. For more info about creating the OpenSearch XML file, see the Understanding OpenSearch Standards (https://msdn.microsoft.com/en-us/library/dd163546.aspx) topic. Use this format to specify the link(s) you wish to add: <https://fabrikam.com/opensearch.xml><https://www.contoso.com/opensearch.xml>

If you disable this setting, any added search engines are removed from your employee's devices.

If you don't configure this setting, the search engine list is set to what is specified in App settings.