DNSレコードタイプの一覧
Obsoleted by RFC 973: MD(3), MF (4), MAILA (254)
Records to publish mailing list subscriber lists in the DNS: MB(7), MG(8), MR(9), MINFO(14), MAILB (253). The intent, as specified by RFC 883, was for MB to replace the SMTP VRFY command, MG to replace the SMTP EXPN command, and MR to replace the "551 User Not Local" SMTP error. Later, RFC 2505 recommended that both the VRFY and EXPN commands be disabled, making the use of MB and MG unlikely to ever be adopted.
Declared "not to be relied upon" by RFC 1123 (with further information in RFC 1127): WKS(11)
Mistakes: NB(32), NBSTAT(33) (from RFC 1002); the numbers are now assigned to NIMLOC and SRV.