Eszett (Sharp-S) again (was: Re: AW: Oustanding issues tracking)

Marcos Sanz/Denic sanz at
Wed May 28 08:20:43 CEST 2008

> (2) If we treat Eszett as a separate character, we create a
> fairly nasty incompatibility between IDNA2003, where it maps to
> "ss" and disappears and IDNA2008, where it is separate.
> Preventing that incompatibility from being a nasty problem would
> require some very careful action by the relevant registries (as
> usual, in the "zone administrator" sense, not just TLD
> registries).  Possibly a well-designed variant strategy would be
> sufficient, possibly not.   We haven't heard from the most
> obvious registries yet as to whether they would be willing to
> deal with this.

If eszett were to be added to the IDNA2008 tables as protocol-valid, DENIC 
probably would, after the standard is passed, allow eszett registration 
under the DE TLD. Since that codepoint was not allowed for registration 
until now (i.e. no mapping eszett->ss occurred within the registry), there 
is no "nasty problem" here from our point of view. When typing eszett in a 
domain name while browsing, some users (IDNA2003) would certainly end up 
at the ss-mapped-name, some other users (IDNA2008) would end up at the 
eszett-name. Still from our point of view (which is not up for debate 
here), usage of variants at the registry would not be an appropriate 
technique for dealing with this issue. On the contrary, it would be my 
recommendation for all ss-mapped-name-registrants to apply for 
registration of the corresponding eszett-name, where applicable. Maybe 
registrars could automatically do this for their customers, I actually 
don't mind. And if the eszett-name would already have been registered by a 
different registrant, chances are very high that the corresponding 
ss-mapped-name-registrant would win a dispute on the eszett-name.

Best regards,

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