Subject: Re: [precis] Stephen Farrell's No Objection on draft-ietf-precis-framework-16: (with COMMENT)

From: John C Klensin <[email-masked]>
Date: Wed, 21 May 2014 15:27:15 -0400

(sorry -- bad address-- resending)

--On Tuesday, 20 May, 2014 20:16 -0600 Peter Saint-Andre
<[email-masked]> wrote:

>...
>> If you wanted, s/This category includes/This currently
>> empty category will include/ would be clearer for me.
>> (Assuming I read it right:-)
> 
> That part is quoted from RFC 5892. However, in the note that
> precedes the quoted text, I suggest that we add the following
> sentence:
> 
>     At the time of this writing (and also at the time that
>     RFC 5892 was published), this category consisted of the
>     empty set; however, that is subject to change as described
>     in RFC 5892.

Unless I misunderstand, if the kinds of exceptions that would
justify using that category were to arise, we'd need separate
review and evaluation systems and approvals for IDNA and PRECIS,
even if they were largely performed by the same people.
Moreover, if PRECIS stays with the profile model it is using
now, we have no basis on which to judge whether this category
(exceptions apply to all protocols and profiles) is adequate or
whether each new version of Unicode requires per-protocol or
per-profile reviews.  That is another reason why a system that
allows or encourages a growing family of profiles gives me the
creeps.  

Six months ago, it would have been sensible to treat the above
comment as largely theoretical: the category was reserved as a
placeholder that we never expected to use.   At this point,
unless an apparent problem that was spotted in Unicode 7.0.0
beta is addressed in a serious way by UTC, the possibility of
having to use the category is very real.  It is also important
to note that the problem was spotted by inspection by a
moderately skilled human after it had successfully gotten
through the usual testing implementations and preliminary review
by the relevant expert.

best,
     john