Re: Last Call: draft-resnick-2822upd (Internet Message Format) toDraft Standard

Dave Crocker <> Mon, 07 April 2008 18:34 UTC

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Date: Mon, 07 Apr 2008 11:34:21 -0700
From: Dave Crocker <>
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Subject: Re: Last Call: draft-resnick-2822upd (Internet Message Format) toDraft Standard
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Pete Resnick wrote:
  >> (1) Partially restore the 822 text, stressing "private use", rather
>> than "experiental".
> I don't think we'll be able to do this; see (3) below.
>> (3) Encourage X-headers for strictly private use, i.e., they SHOULD 
>> NOT be used in any context in which interchange or communication 
>> about independent systems is anticipated and therefore SHOULD NOT be 
>> registered under 3683.
> I think this is DOA. There are many folks (myself included) who think 
> this should not be encouraged in any way, shape, or form.


One of the lessons of the community's 30+ years of protocol work is that 
specification details which are actually usage guidance, rather than concrete 
interoperability details, often have little impact on a global community.  The 
community formulates its own preferences.

When X- as original proposed, I thought it was marvelously clever.  I still do.

But it doesn't work.

While it does protect a privately-developed header field label from being 
preempted by a standards process, it creates a much more serious problem of 
moving from private-use to public standards and having to (try to) re-label the 
field.  This is a highly disruptive impact./

In other words, if the model is true that existing practices get standardized -- 
and in this realm they often are, I think -- then we need to design things to 
make the transition from private-to-public be comfortable.  Defining a 
private-use naming space runs counter to that goal.

Valuable lesson.  We should learn it.



   Dave Crocker
   Brandenburg InternetWorking
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