Re: [EAI] Comments on draft-ietf-eai-imap-utf8-07

[Alexey Melnikov <[e-mail]>]

Barry Leiba wrote:

>Hi, Pete.
>
Hi Barry,

>>>OLD
>>> The UTF8=ONLY capability implies the UTF8 base capability, the
>>> UTF8=ALL capability and the UTF8=APPEND capability.  A server which
>>> advertises UTF8=ONLY need not advertise the three implicit
>>> capabilities.
>>>
>>>Oy.  This makes parsing the capability string complicated, and should
>>>be earlier in the document.  It'd be good to make this clear at the
>>>beginning, when the UTF8 capability is first mentioned. 
>>>
>>I'm not sure what you want here. Something in the "UTF8" section that says,
>>"See below"? Left as is for now. Fix in an RFC Editor Note if need be.  
>>
>When one starts reading the document, one gets to this:
>
>---------------------------------------------
>3.  UTF8 IMAP Capability
>
>   The basic "UTF8" capability indicates the server supports UTF-8
>   quoted strings, the "UTF8" parameter to SELECT and EXAMINE, and UTF-8
>   responses from the LIST and LSUB commands.
>---------------------------------------------
>
>It's only later, when one gets to section 7, which I quote above, that
>one finds that it's not sufficient to look for "UTF8": one also has to
>look for "UTF8=ONLY".  And we don't say that UTF8=ALL, UTF8=APPEND, or
>UTF8=USER imply the base UTF8.  So if UTF8=ONLY is special, I think we
>need to say that right up there at the start of section 3, so it's
>clear.  Or else we say that the presence of *any* "UTF8=" capability
>implies the base UTF8, and say *that* in section 3, so it's clear
>right up front as to what capability string(s) need to be checked for.
>
>D'you see what I'm getting at?
>
(As the responsible AD) After rereading various pieces of the document, 
I agree this is not clear.


(As a WG participant) Here is my understanding how things should work:

UTF8=USER is useful by itself, so I think it should be independent of 
all other UTF8* capabilities. For example it should be possible to only 
support UTF8=USER (non EAI IMAP server, but which accepts UTF-8 
usernames/passwords), or support all other EAI functions, without 
supporting UTF-8 username/password (e.g. a legacy authentication database).

I think UTF8=APPEND should be independent of other UTF8* capabilities. 
Allowing for EAI APPEND might require quite a bit of extra work.

Both UTF8=ALL and UTF8=ONLY are related to UTF8 capability. We can 
either define them as implying UTF8, or say that if one of them is 
advertised, then UTF8 MUST also be advertised. Moreover, I think 
UTF8=ONLY implies UTF8=ALL.
One can also argue that UTF8=ONLY implies UTF8=APPEND. I would be Ok 
either way, but one way or another this needs to be stated explicitly.

Comments?