Transferring a domain name from one registrar company to another traditionally entails the use of a unique authorization code, which different registrar companies call an EPP key, a domain name password or an AuthInfo code. This code can be used as a protection mechanism against unauthorized transfer attempts with all gTLD and with most ccTLD extensions. It can be obtained only by the owner of the particular domain name and is issued by the current registrar company. It must be given to the new registrar company because the transfer cannot be initiated without it. The code is case-sensitive and often includes numbers and special symbols, so as to stop unauthenticated individuals from deciphering it. Some registrar companies even change the codes of domains registered through them after a particular period of time for even greater security.