Transferring a domain from one registrar company to another normally involves the use of a unique transfer authorization code, which different companies refer to as an EPP key, a domain name password or an AuthInfo code. This code can be used as a security measure against unsanctioned transfer attempts with all generic and with most country-code extensions. The code can be obtained only by the domain name owner and is provided by the present domain name registrar company. It must be given to the new domain name registrar company because the transfer cannot be started without it. The code is case-sensitive and traditionally includes numbers and special symbols, so as to prevent unauthenticated persons from hijacking it. Some registrar companies even alter the codes of domains registered through them periodically for better security.