Comments on IDNA Bidi

Shawn Steele Shawn.Steele at
Mon Jan 14 19:33:25 CET 2008

> Now I'm confused.  Keep in mind that, in an actual URL, having
> an IDN in anything but A-label (punycode processed) form is
> invalid.

That seems a bit of a narrow view.  The point of IDN is to allow a human readable version of a URL, such as on a business card.  In that case the URL certainly contains non-punicode labels.

Certainly some standards don't allow > 0x7f, so in that case the punicode form is required internally, but in other layers Unicode MUST be allowed, otherwise you couldn't enter an IDN name into the browser's address bar.  In practice browsers also allow Unicode forms in the HTML itself, so I believe that it should be understood that the ASCII hack applies mostly to the DNS layer.

- Shawn

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