[apps-discuss] Slash and version number in Authentication-results: header field (was: I-D Action: draft-ietf-appsawg-rfc5451bis-02.txt)

[S Moonesamy <[e-mail]>]

Hi Alexey,

Scott Kitterman mentioned [1] that the following:

   authres-header = "Authentication-Results:" [CFWS] authserv-id	
	[ [CFWS] "/" [CFWS] authres-version ]

  'is an incompatible change and if you really want to make it, you should
   bump the version number.  I checked and with authres, your example is
   mis-parsed.

	Authentication-Results: example.org/1; none

   In this example, the authserv-id is "example.org", but authres, using the
   RFC 5451 ABNF parses this and determines the authserv-id is "example.org/1"'

Murray Kucherawy commented that he has "yet to see a single 
implementation that includes a version number in its output, though 
there are some that do look for it" [2].  John Levine responded that 
his implementation does [3].  He also mentioned that the introduction 
of the slash (see ABNF) creates an incompatibility.

There is also the following in Section 5 of draft-ietf-appsawg-rfc5451bis-02:

   "An MTA SHOULD remove any instance of this header field bearing a
    version (express or implied) that it does not support."

Will the addition of the slash cause an interoperability issue?

Regards,
S. Moonesamy

1. http://www.ietf.org/mail-archive/web/apps-discuss/current/msg09460.html
2. http://www.ietf.org/mail-archive/web/apps-discuss/current/msg09463.html
3. http://www.ietf.org/mail-archive/web/apps-discuss/current/msg09465.html