Transferring a domain from one company to another commonly entails the use of a unique domain authorization code, which different companies refer to as an EPP authentication code, a domain password or an Auth code. This code can be used as a safety mechanism against unauthorized transfers with all gTLD and with most ccTLD extensions. The code can be obtained only by the owner of the particular domain name and is provided by the present domain name registrar company. It must be given to the new registrar company because the transfer cannot be started without it. The code is case-sensitive and commonly contains digits and special characters, so as to stop unauthorized people from cracking it. Some registrars even change the codes of domain names registered through them after a certain period of time for greater security.