Silly DNS question

[Joshua Judson Rosen]

Thomas Charron <twaffle at gmail.com> writes:
>
>   Is an _ allowed in a DNS name?

DNS-SD, DKIM, ADSP, and a whole bunch of other parts of the greater
internet infrastructure think so--actually, they depend on it.

But "allowed" is a long way away from "in general good taste".

I take "_" in domains as being sort-of like backslashes in `English'
and programming text; presumably, the reason that it got designed-into
computing-architecture the way it did was because nobody in their
right mind was supposed to have been using it casually.

In fact, if I'm remembering this correctly..., the last time I looked at
the DNS RFCs, using anything other than ASCII *alphanumerics and hyphens*
was discouraged.

Of course, this is coming from someone whose .signature is in UTF-8....

-- 
"Don't be afraid to ask (λf.((λx.xx) (λr.f(rr))))."