 These "de facto" standards define CRAM-MD5 as an authentication method for the email mailbox-management protocols POP and IMAP.CRAM-MD5 is one of the authentication methods supported by Simple Authentication and Security Layer (SASL), defined in 2006 by RFC 4422, which supersedes the 1997 standard RFC 2222.The Internet Assigned Numbers Authority (IANA) maintains a registry of SASL mechanisms, including CRAM-MD5, for limited use.