Re: [dmarc-ietf] DMARC bis: ticket 49: remove normative requirement on policy tag placement

["Murray S. Kucherawy" <[e-mail]>]

On Fri, May 15, 2020 at 11:27 AM Seth Blank <seth=
[e-mail]> wrote:

> https://trac.ietf.org/trac/dmarc/ticket/49
>
> The penultimate paragraph of
> https://tools.ietf.org/html/rfc7489#section-6.3 states:
>
> the "v" and "p" tags MUST be present and MUST
>    appear in that order.
>
> While the v= tag pretty universally appears first, the p= tag does not in
> many records, and no implementation appears to care.
>
> The v= tag must appear first, or the policy discovery mechanism as defined
> in https://tools.ietf.org/html/rfc7489#section-6.6.3 would break.
>
> But there doesn't appear to be any real reason to keep the normative
> requirement that the p= tag MUST be second in the record after the v= tag,
> nor does this requirement seem to have any impact on interoperability or
> general record parsing in theory or in practice.
>
> Should we remove this normative requirement?
>

It's been a while since the original discussion, but I can't remember why
the requirement is there in the first place.  The only benefit I can think
of is that having "v=" first lets you decide very quickly if you care to
continue, but the savings is really pretty small.

-MSK, devoid of hat