Intranet Sites: Include all local (intranet) sites not listed in other zones

This policy setting controls whether local sites which are not explicitly mapped into any Security Zone are forced into the local Intranet security zone. If you enable this policy setting local sites which are not explicitly mapped into a zone are considered to be in the Intranet Zone. If you disable this policy setting local sites which are not explicitly mapped into a zone will not be considered to be in the Intranet Zone (so would typically be in the Internet Zone). If you do not configure this policy setting users choose whether to force local sites into the Intranet Zone.