Potential Erratum re. length limits in RFC 5890

Andrew Sullivan ajs at shinkuro.com
Tue Sep 28 16:00:28 CEST 2010

On Tue, Sep 28, 2010 at 09:20:21AM -0400, John C Klensin wrote:

> characters and zero or more combining characters).  A 63
> user-abstract character limit is an upper limit that is unlikely
> to be reached if non-ASCII characters are present (impossible in
> the Unicode encoding), but the WG strongly rejected earlier text
> that imposed octet limits on the length of U-labels.

This is what I recall, too.  There was too much implicit confusion of
U-labels and A-labels, and therefore the upshot was

    - the hard limit is the one imposed by the resulting A-label by
      DNS; and

    - any other limit was just a consequence of that.

If it's really important, I can maybe go back and dig up the thread.


Andrew Sullivan
ajs at shinkuro.com
Shinkuro, Inc.

More information about the Idna-update mailing list