Re: [idn] Name forms in the requirements doc

[Harald Tveit Alvestrand <Harald@Alvestrand.no>]

At 15:16 16.06.2000 -0700, Paul Hoffman / IMC wrote:
>The last paragraph of section 1.2 of the requirements document says:
>
>>The form specified for most protocols using the DNS is a limited form of
>>the master file format domain name. This limited form is defined in
>>[RFC1034] Section 3.5 and [RFC1123]. In most implementations of
>>applications today, domain names in the Internet have been limited to
>>the much more restricted forms used, e.g., in email.   Those names are
>>limited to the ASCII upper and lower-case characters (interpreted in a
>>case-independent fashion), the digits, and the hyphen, with the further
>>restrictions that a name may not consist entirely of digits and that a
>>hyphen cannot occur at the beginning or end of a component or following
>>another hyphen.
>
>Where did the restrictions of "may not consist entirely of digits" and "a 
>hyphen cannot occur...following another hyphen" come from? I cannot find 
>those in 1034 or 1123.

RFC 952, October 1985 is the original "hostname" spec.
However, note this from RFC 1123 2.1:

>            If a dotted-decimal number can be entered without such
>            identifying delimiters, then a full syntactic check must be
>            made, because a segment of a host domain name is now allowed
>            to begin with a digit and could legally be entirely numeric
>            (see Section 6.1.2.4).  However, a valid host name can never
>            have the dotted-decimal form #.#.#.#, since at least the
>            highest-level component label will be alphabetic.

All digit segments *are* allowed, and in common use in Chinese .com domains,
for some reason.
The domainname i--d.com is also registered (by someone in Vienna).
So I think both restrictions are false and should not be deleted.

                   Harald



--
Harald Tveit Alvestrand, EDB Maxware, Norway
Harald.Alvestrand@edb.maxware.no