Subject: [precis] [Technical Errata Reported] RFC7700 (4570)

From: RFC Errata System <[email-masked]>
Date: Tue, 22 Dec 2015 20:58:26 -0800 (PST)

The following errata report has been submitted for RFC7700,
"Preparation, Enforcement, and Comparison of Internationalized Strings Representing Nicknames".

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You may review the report below and at:
http://www.rfc-editor.org/errata_search.php?rfc=7700&eid=4570

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Type: Technical
Reported by: Sam Whited <[email-masked]>

Section: 2.3

Original Text
-------------
An entity that performs enforcement according to this profile MUST
   prepare a string as described in Section 2.2 and MUST also apply the
   following rules specified in Section 2.1 in the order shown:

   1.  Additional Mapping Rule
   2.  Normalization Rule
   3.  Directionality Rule

   After all of the foregoing rules have been enforced, the entity MUST
   ensure that the nickname is not zero bytes in length (this is done
   after enforcing the rules to prevent applications from mistakenly
   omitting a nickname entirely, because when internationalized
   characters are accepted, a non-empty sequence of characters can
   result in a zero-length nickname after canonicalization).

Corrected Text
--------------
An entity that performs enforcement according to this profile MUST
   prepare a string as described in Section 2.2 and MUST also apply the
   following rules specified in Section 2.1 in the order shown:

   1.  Additional Mapping Rule
   2.  Case Mapping Rule
   3.  Normalization Rule

   After all of the foregoing rules have been enforced, the entity MUST
   ensure that the nickname is not zero bytes in length (this is done
   after enforcing the rules to prevent applications from mistakenly
   omitting a nickname entirely, because when internationalized
   characters are accepted, a non-empty sequence of characters can
   result in a zero-length nickname after canonicalization).

Notes
-----
There is no directionality rule to be applied during enforcement as the directionality rule is part of NFKC, the case mapping rule (as mentioned in section 2.1).

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RFC7700 (draft-ietf-precis-nickname-19)
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Title               : Preparation, Enforcement, and Comparison of Internationalized Strings Representing Nicknames
Publication Date    : December 2015
Author(s)           : P. Saint-Andre
Category            : PROPOSED STANDARD
Source              : Preparation and Comparison of Internationalized Strings
Area                : Applications and Real-Time
Stream              : IETF
Verifying Party     : IESG

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From: Sam Whited <[email-masked]>
Date: Wed, 23 Dec 2015 09:09:51 -0600

Hi all,

After submitting this yesterday I had a discussion with Christian
Schudt about it and he pointed out that you probably want to be able
to display the text output by the enforce operation, and therefore
this was most likely a deliberate change. With that in mind, I'd like
to ammend my suggestions somewhat:

The directionality rule should still be removed from the list of rules
in section 2.3 as well as the list in section 2.4 (there is no
directionality rule, so having it in the order of operations is just
confusing), and section 2 item 3 should be updated to clarify that
Unicode default case folding only needs to be applied during the
comparison step (right now it states that it "MUST be applied" which
is ambiguous since it doesn't list what step (or steps) need to apply
it and makes it seem like it should be part of the enforcement step).

Best,
Sam

-- 
Sam Whited
pub 4096R/54083AE104EA7AD3
https://blog.samwhited.com