Transferring a domain name from one registrar company to another usually involves the use of a unique authorization code, which different registrar 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 unauthorized transfers with all gTLD and with most ccTLD extensions. It can be obtained only by the domain name owner and is provided by the current domain name registrar company. It must be given to the new registrar because the transfer cannot be initiated without it. The code is case-sensitive and commonly comprises of numbers and special characters, so as to obstruct unauthorized persons from cracking it. Some domain name registrars even alter the codes of domains registered through them after a given interval of time for better safety.