Transferring a domain from one registrar company to another commonly involves the use of a special authorization code, which different registrar 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 unapproved transfer attempts with all gTLD and with most ccTLD extensions. The code can be obtained only by the owner of the given domain and is provided by the current domain registrar company. It must be given to the new registrar because the transfer process cannot be started without it. The code is case-sensitive and frequently includes numbers and special characters, so as to hinder unauthenticated persons from guessing it. Some domain name registrars even change the codes of domain names registered through them after a given period of time for better security.