A stealth server is a server that answers authoritatively for a zone, but is not listed in that zone's NS records. Stealth servers can be used as a way to centralize distribution of a zone, without having to edit the zone on a remote name server. When the master file for a zone is on a stealth server in this way, it is often referred to as a hidden primary configuration. Stealth servers can also be a way to keep a local copy of a zone for rapid access to the zone's records, even if all official name servers for the zone are inaccessible.