Erik Fair | 31 May 07:15 2011

Re: NetBSD Security Advisory 2011-005: ISC dhclient hostname field shell metacharacter injection

Not all domain names are host names. Most of the restrictions on hostnames do indeed date from the days of
hosts.txt, but most of those restrictions have come forward in Internet E-mail standards.

It is still illegal to have a "_" in a host name. You can stick 'em in any domain name that isn't going to be used
as a host name ...

And, yeah, IDN is screwing up all kinds of things.

	Erik <fair <at>>