RFC 5890, "Internationalized Domain Names for Applications (IDNA): Definitions and Document Framework", August 2010

Errata ID: 4696
Status: Verified
Type: Editorial
Publication Format(s) : TEXT
Reported By: Juan Altmayer Pizzorno
Date Reported: 2016-05-17
Verifier Name: Alexey Melnikov
Date Verified: 2016-10-07

Section 4.2 says:

Because A-labels (the form actually used in the
DNS) are potentially much more compressed than UTF-8 (and UTF-8 is,
in general, more compressed that UTF-16 or UTF-32), U-labels that
obey all of the relevant symmetry (and other) constraints of these
documents  may be quite a bit longer, potentially up to 252 characters
(Unicode code points).

It should say:

Because A-labels (the form actually used in the
DNS) are potentially much more compressed than UTF-8 (and UTF-8 is,
in general, more compressed that UTF-16 or UTF-32), U-labels that
obey all of the relevant symmetry (and other) constraints of these
documents  may be quite a bit longer, potentially up to 252 octets.
                                                        ^^^^^^^^^^

Notes:

Similar to Erratum 4695.

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