what's a valid domain name?

[Barry Margolin]

In article <mailman.1586.1296424051.555.bind-users at lists.isc.org>,
 Vytautas Grigaliunas <vyto at fnal.gov> wrote:

> What is the status of "dotted" hostnames - i.e. a period in the hostname 
> portion of a domain name ?
> 
> At one point they were allowed, I believe ? What is the latest official RFC ?

I don't think they've every been allowed.  Why would you need to do 
this, instead of just using another level of subdomain?  To get a 
literal period into a label, you need to escape it, e.g. 
foo\.bar.company.com instead of foo.bar.company.com.  The latter is 
allowed, always has been, and is quite common.

-- 
Barry Margolin, barmar at alum.mit.edu
Arlington, MA
*** PLEASE don't copy me on replies, I'll read them in the group ***