Transferring a domain name from one company to another generally entails the use of a special domain authorization code, which different registrar companies refer to as an EPP key, a domain password or an AuthInfo code. This code can be used as a security measure against unapproved transfer attempts with all gTLD and with most ccTLD extensions. It can be obtained only by the owner of the particular domain and is provided by the current registrar. 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 frequently contains digits and special characters, so as to hinder unauthenticated people from cracking it. Certain domain registrars even alter the codes of domains registered through them after a certain interval of time for even better security.