Hostname Naming Compliance

Kevin Darcy kcd at
Fri Feb 27 02:53:51 UTC 2009

Matus UHLAR - fantomas wrote:
>> Mark Andrews wrote:
>>> 	When does it stop?  What will be the next character you
>>> 	"just have to have"?  At the moment you have 1 inter label
>>> 	seperator and 1 intra label seperator.  That should be
>>> 	enough for anyone.
> On 25.02.09 08:49, Peter Laws wrote:
>> Like 640k of memory.
> the main effect of allowing underscores would be that some companies would
> want/need to buy much more domains, e.g.
> a-b
> a_b
> and 
> a-b-c
> a_b_c
> a_b-c
> a-b_c
> I don't see any benefit in that.
>> Unicode is coming (as fast as IPv6, maybe faster :), so maybe it /is/ time 
>> to update the naming standards.
> and maybe it is not. If people can't behave, adjusting standards may be the
> worst solution.
But, as far as I can tell, there's no *practical* reason to disallow 
underscores, other than the fact that it may trip the standards-checking 
code of some _other_ piece of software. So, piece of software A 
disallows underscores because it's worried about causing a problem for 
piece of software B, and piece of software B keeps the restriction 
because it's worried about about causing a problem for piece of software 
C, and piece of software C keeps the restriction because it's worried 
about causing a problem for piece of software A.

Do you see how self-defeating that is? Everyone is looking out for 
everyone else, yet there is no actual *real* problem with allowing 
underscores. They're all just trying to protect each other against an 
imagined threat.

I've heard that in the old old days (70s, perhaps earlier) some 
teletypes had a problem distinguishing between an underscore and a 
backspace. That was a real honest-to-goodness *problem* with 
underscores, and is probably why underscore was banned from hostnames in 
the first place. But those teletypes are long gone. Rusted away or in a 
museum somewhere. Get over it.

I agree with not changing standards to accommodate "bad behavior". But, 
at the same time, the standards need to have a practical basis, not be 
arbitrary or just a carryover from decades ago. As far as I can tell, 
the underscore restriction, in particular, is just a legacy carryover 
and has no practical use.

- Kevin

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