registrar
What is a domain's auth code and why do I need it?
Posted June 1st, 2007 by markjrDomains in the .com, ,net, .org, .biz and .info TLDs (aka .CNOBI) use a registry protocol called "EPP" to communicate between the registrars and registry.
Under this protocol, a domain "auth code" is a small random code assigned to each domain name and is required in order for a domain name to be transferred from one registrar to another.