[idn] Re: Hostname syntax

["Eric A. Hall" <ehall@ehsco.com>]

David Hopwood wrote:

> "Eric A. Hall" wrote:

> > Until the 2-char rule inherited from 952 by 1035 is overthrown

> What 2-character rule? There is nothing in either the 952, 1035, or
> 1123 syntaxes to prohibit single-character labels.

The last sentence from the following excerpt of RFC 952:

> | 1. A "name" (Net, Host, Gateway, or Domain name) is a text string up
> | to 24 characters drawn from the alphabet (A-Z), digits (0-9), minus
> | sign (-), and period (.).  Note that periods are only allowed when
> | they serve to delimit components of "domain style names". (See
> | RFC-921, "Domain Name System Implementation Schedule", for
> | background).  No blank or space characters are permitted as part of a
> | name. No distinction is made between upper and lower case.  The first
> | character must be an alpha character.  The last character must not be
> | a minus sign or period.  A host which serves as a GATEWAY should have
> | "-GATEWAY" or "-GW" as part of its name.  Hosts which do not serve as
> | Internet gateways should not use "-GATEWAY" and "-GW" as part of
> | their names. A host which is a TAC should have "-TAC" as the last
> | part of its host name, if it is a DoD host.  Single character names
> | or nicknames are not allowed.

"Single character names or nicknames are not allowed."

-- 
Eric A. Hall                                        http://www.ehsco.com/
Internet Core Protocols          http://www.oreilly.com/catalog/coreprot/