In article <alpine.LFD.2.20.1509111502500.29138@xxxxxxxxxxxxxx> you write: >On Fri, 11 Sep 2015, John C Klensin wrote: > >>> So you are claiming that DNS can take any UTF-8 character? > >> base of DNS servers did not handle well. But there was never a >> claim that the DNS couldn't store characters coded in UTF-8 or, >> for that matter, any bit sequence in octets. The latter >> capability is made quite clear in the DNS base documents >> (1034/1035) and RFC 2181. > >We are not talking about the RDATA part - we are talking about the DNS >label (aka hostname or qname). ... Hold it. Every hostname is a DNS name, but most possible DNS names are not hostnames. To take an obvious example, none of the names that this draft specifies for the names of PGP keys are hostnames, because hostnames are limited to ASCII letters, digits, and hyphens, and the key names all contain underscores. Since they're not hostnames, I agree with John K that there is no reason to limit the representation of a local-part to hostname characters. Names in the DNS really can be arbitrary octets, up to 63 octets per component, and the DNS handles them completely transparently (other than the rule to fold ASCII upper and lower case letters.) If you put UTF-8 names directly into the DNS, your master file would be kind of ugly but it would work fine. I've done it. R's, John PS: It's dismaying to see confusion about basic DNS concepts at such a late point.