> The seminal definition (must start with a letter) was from RFC 952. Then it was lifted in RFC 1123: “One aspect of host name syntax is hereby changed: the restriction on the first character is relaxed to allow either a letter or a digit.
This relaxation was for 3com because you couldn’t very well exclude Bob Metcalf of all people in your networking protocol! I remember there was a bit of chatter at the time about a domain beginning with a digit.
This relaxation was for 3com because you couldn’t very well exclude Bob Metcalf of all people in your networking protocol! I remember there was a bit of chatter at the time about a domain beginning with a digit.