Transferring a domain name from one company to another traditionally entails the use of a special domain name authorization code, which different registrar companies refer to as an EPP authorization code, a domain password or an AuthInfo code. This code can be used as a security measure against unsanctioned transfer attempts with all gTLD and with most ccTLD extensions. It can be obtained only by the owner of the particular domain and is issued by the present registrar. It must be given to the new registrar because the transfer cannot be started without it. The code is case-sensitive and frequently comprises of numbers and special symbols, so as to prevent unauthorized persons from guessing it. Certain domain name registrars even alter the codes of domains registered through them after a given interval of time for better security.