Gervase Markham gerv at
Fri Mar 7 15:59:11 CET 2008

John C Klensin wrote:
> Partially because the prohibition in 3490 on display of punycode
> didn't work (some browser vendors now view display of punycode
> in varying circumstances as a feature) 

"A feature" is a bit strong; "the least worst thing to do" is probably 
better. When displaying the decoded version would lead to risk to the 
user, and displaying nothing is not an option, the punycode version at 
least has the significant advantages that it's a) always readable and b) 
unique to that domain.

Ideally, Firefox would never display punycode in normal browsing, 
because all registries would have homograph policies and would have 
registered for the whitelist. I admit it does continue to surprise me 
that various large GTLDs have not attempted to register. But I guess 
that's their business decision.


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