Re: [apps-discuss] "X-" revisited

Dave CROCKER <> Tue, 28 June 2011 18:56 UTC

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Date: Tue, 28 Jun 2011 11:56:19 -0700
From: Dave CROCKER <>
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To: Al Costanzo <>
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Subject: Re: [apps-discuss] "X-" revisited
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On 6/28/2011 10:27 AM, Al Costanzo wrote:
> Originally, if I remember, this "X-" was used by vendors, for specific headers
> that they needed and wanted to be "ignored or not used by other until possibly
> they were done with the design and implementation.
> Was it not?

When I was doing RFC822, there was an associated discussion list.  RFC822 was 
really only a refinement of RFC733.  There was an additional 5 years of email 
experience and a better understanding of some issues, and the task was merely 
tweaking the spec.  The list was informal and collaborative.  There was no IETF 
and no formal standardization in those days, but absent formal processes, it was 
like a working group.(*)

I do not remember who posted the idea of X-, except that it wasn't me, but as I 
recall it got immediate support.  I, for one, thought it a very cool idea.

However, this was long before "vendors" were much of an issue, by nearly 10 
years.  I don't recall any sense, in those days, of "vendor" as a distinct class 
within our work.

However various folk did private stuff.  Lots of experimentation in those days. 
  So the concern was that somebody's private stuff, which invented its own 
header field, would get stepped on by a later group/standards process that chose 
the same header field name.  This was merely to protect against that happening.

Alas, we gave no thought to /wanting/ the private effort to become 'standardized'.


(*)  In 1977, RFC733 was the first RFC to declare itself a standard.  However 
there was no reall standards process.  We got permission from ARPA to use the 
word in the title in order to flag to the community some strong pressure to move 
from whatever ad hoc formats were being used to this one.  In spite of the ARPA 
approval, there was a firestorm of indignation that we would be so presumptious 
as to /demand/ that folks adopt the spec.  That just wasn't they way things were 
adopted in those days...


   Dave Crocker
   Brandenburg InternetWorking