Subject: RE: Working toward unity on XML

From: "Jim Lyon" <[email-masked]>
Date: Tue, 15 Jun 2004 23:39:39 -0700

I think that Greg has done an excellent write-up of the positions.

Position 1 was originally taken by Microsoft Caller ID.
Position 2 was originally taken by SPF.
I see position 3 as the best of both worlds, and heartily support it.
I see position 4 as the worst of both worlds.
I believe that "syntax" extensibility will be crucial in the future.
I believe that "feature" extensibility has a positive but small value,
but probably isn't worth the cost.

Just to be clear, the current compromise draft takes position 3 (parsers
support both SPF and XML, domain owners publish one or the other). It
also enables "syntax" extensibility.  While it doesn't go out of its way
to support "feature" extensibility -- there's no ALT mechanism, for
example -- it doesn't completely rule it out, either.

-- jimbo

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From: Margaret Olson <[email-masked]>
Date: Wed, 16 Jun 2004 08:48:40 -0400

I

> but probably isn't worth the cost.

I see authenticating a domain as fairly well understood at this point, 
but the necessary additional services are just beginning to emerge. You 
need to tie the reputation and accreditation to the authentication, and 
we may find that it's crucial to do so in the MARID record. Reputation 
and accreditation are new and poorly understood areas, so I would not 
credit anyone's crystal ball on what will be required. Given that, I 
think syntax extensibility is critical and that the possibility of 
feature extensibility is also critical, with the caveat that the 
feature extensibility must be backwards compatible, an exercise that by 
definition has to be left to the designers of the new feature. With 
syntax extensibility you can in theory get some backwards compatible 
semantic extensibility.

So like Jim, I heartily support position 3, which I would define as 
backwards compatibility for the existing SPF syntax. I'll observe that 
SenderID has a feature extension (SUBMITTER, the PRD algorithm) over 
SPF.

Many thanks to Greg for taking the time to write up the positions.

Margaret.

(I have not read the current draft closely enough to understand how 
publishing domains express their wish to be treated as SPF v1 or 
SenderID so I have held off on commenting on how well I think that will 
work.)